Added preliminary (and unfinished) xcircuit integration.
diff --git a/sky130/xcircuit/sky130.xcircuitrc b/sky130/xcircuit/sky130.xcircuitrc
new file mode 100644
index 0000000..5cd2f80
--- /dev/null
+++ b/sky130/xcircuit/sky130.xcircuitrc
@@ -0,0 +1,8 @@
+set XCOps(liboverride) 1
+config search libraries .:STAGING_PATH/TECHNAME/libs.tech/xcircuit:$XCIRCUIT_LIB_DIR
+library make Generic
+library 1 load generic.lps
+library make TECHNAME_analog
+library 2 load sky130_fd_pr
+library make TECHNAME_digital
+library 3 load sky130_fd_sc_hd