Add some new labeler rules and update the existing ones to match actu…

…al existing labels

.github/labeler.yml

@@ -1,8 +1,14 @@
-campaign:
+Campaigns:
   - data/campaigns/**/*
 
-xcode:
+macOS:
   - projectfiles/Xcode/**/*
+  - src/macosx/*
 
-unit_tests:
+Unit Tests:
   - data/test/**/*
+
+UI: ["src/gui/**/*", "data/gui/**/*", "data/schema/gui.cfg"]
+Units: ["src/units/**/*", "data/core/units/**/*", "data/core/images/units/**/*"]
+Terrain: ["src/terrain/**/*", "data/core/terrain.cfg", "data/core/terrain_graphics/*", "data/images/terrain/**/*"]
+Lua API: ["src/scripting/**/*", "data/lua/**/*"]