Updates default_fanout_load for the standard cell library

Fixes The-OpenROAD-Project/OpenROAD#2339

- [x] Tests pass
- [x] Appropriate changes to README are included in PR
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_1v98.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_1v98.lib
index 1a51ed1..6289846 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_1v98.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_1v98.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 125 ; 
   nom_voltage : 1.98 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_3v60.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_3v60.lib
index 44cbb57..c93d257 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_3v60.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_3v60.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 125 ; 
   nom_voltage : 3.6 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_5v50.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_5v50.lib
index 5e0fad1..cf4ef04 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_5v50.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_125C_5v50.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 125 ; 
   nom_voltage : 5.5 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_1v98.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_1v98.lib
index bb81fc7..d87970e 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_1v98.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_1v98.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : -40 ; 
   nom_voltage : 1.98 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_3v60.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_3v60.lib
index 227c098..5b2aecc 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_3v60.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_3v60.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : -40 ; 
   nom_voltage : 3.6 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_5v50.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_5v50.lib
index dd7d9e9..e84fc45 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_5v50.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ff_n40C_5v50.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : -40 ; 
   nom_voltage : 5.5 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_1v62.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_1v62.lib
index 6965b80..c2a912a 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_1v62.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_1v62.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 125 ; 
   nom_voltage : 1.62 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_3v00.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_3v00.lib
index 1fbff61..0d318a7 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_3v00.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_3v00.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 125 ; 
   nom_voltage : 3 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_4v50.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_4v50.lib
index 80acc0b..b997184 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_4v50.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_125C_4v50.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 125 ; 
   nom_voltage : 4.5 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_1v62.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_1v62.lib
index b8ae0b8..905db4b 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_1v62.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_1v62.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : -40 ; 
   nom_voltage : 1.62 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_3v00.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_3v00.lib
index 08ebbe6..f1bd1c0 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_3v00.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_3v00.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : -40 ; 
   nom_voltage : 3 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_4v50.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_4v50.lib
index 70f3b06..9f21fcc 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_4v50.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__ss_n40C_4v50.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : -40 ; 
   nom_voltage : 4.5 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_1v80.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_1v80.lib
index 52123d5..576e041 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_1v80.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_1v80.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 25 ; 
   nom_voltage : 1.8 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_3v30.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_3v30.lib
index 7c9dce8..bd3c9a1 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_3v30.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_3v30.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 25 ; 
   nom_voltage : 3.3 ; 
diff --git a/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_5v00.lib b/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_5v00.lib
index 5c8599c..9bf8c8f 100644
--- a/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_5v00.lib
+++ b/liberty/gf180mcu_fd_sc_mcu9t5v0__tt_025C_5v00.lib
@@ -31,7 +31,8 @@
   slew_lower_threshold_pct_fall : 30 ; 
   slew_lower_threshold_pct_rise : 30 ; 
   slew_upper_threshold_pct_fall : 70 ; 
-  slew_upper_threshold_pct_rise : 70 ; 
+  slew_upper_threshold_pct_rise : 70 ;   
+  default_fanout_load : 1.0000000000 ;  
   nom_process : 1 ; 
   nom_temperature : 25 ; 
   nom_voltage : 5 ;