chore: updating package's .gitignore

Attempting to save public/cim/README.md while ignoring cim xml files

Signed-off-by: Juan Muñoz <[email protected]>

Author: juancho0202

packages/compas-open-scd/.gitignore

@@ -21,5 +21,4 @@
 /build/
 /out-tsc/
 
-/public/cim/
-!/public/cim/README.md
+/public/cim/**/*.xml

packages/compas-open-scd/public/cim/README.md

@@ -0,0 +1,8 @@
+Directory containing fixed files for the 'Import from API' plugin, namely:
+
+- cim-eq-hoorn-v3.xml
+- cim-eq-makkum.xml
+- cim-eq-winselingseweg-voorbeeld.xml
+- EQ-entsoe-voorbeeld.xml
+
+Without these files, the 'Import from API' doesn't work and the hardcoded files cannot be opened.