Fix JSON for muxes using udp_mux_4to2.

Fixes to the model for `udp_mux_4to2` cause the JSON layout output to now
include the cell.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

README.rst

diff --git a/README.rst b/README.rst
index c527d5d..0382425 100644
--- a/README.rst
+++ b/README.rst
@@ -1,5 +1,5 @@
 :lib:`sky130_fd_sc_ms` - SKY130 Medium Speed Digital Standard Cells (SkyWater Provided)
 =======================================================================================
 
-Initial release of version (0, 0, 0).
+Initial release of version (0, 0, 1).
 

cells/conb/sky130_fd_sc_ms__conb_1.lef

diff --git a/cells/conb/sky130_fd_sc_ms__conb_1.lef b/cells/conb/sky130_fd_sc_ms__conb_1.lef
index 1478055..a3b1bd2 100644
--- a/cells/conb/sky130_fd_sc_ms__conb_1.lef
+++ b/cells/conb/sky130_fd_sc_ms__conb_1.lef
@@ -26,6 +26,7 @@
   SYMMETRY X Y ;
   SITE unit ;
   PIN HI
+    ANTENNADIFFAREA  0.000000 ;
     ANTENNAPARTIALMETALSIDEAREA  0.182000 ;
     DIRECTION OUTPUT ;
     USE SIGNAL ;
@@ -36,6 +37,7 @@
     END
   END HI
   PIN LO
+    ANTENNADIFFAREA  0.000000 ;
     ANTENNAPARTIALMETALSIDEAREA  0.182000 ;
     DIRECTION OUTPUT ;
     USE SIGNAL ;