Add some extra libraries to release packages

Author: raysan5

.github/workflows/windows.yml

@@ -102,6 +102,9 @@ jobs:
     - name: Generate Artifacts
       run: |
         copy /Y .\src\raylib.h .\build\${{ env.RELEASE_NAME }}\include\raylib.h
+        copy /Y .\src\raymath.h .\build\${{ env.RELEASE_NAME }}\include\raymath.h
+        copy /Y .\src\rlgl.h .\build\${{ env.RELEASE_NAME }}\include\rlgl.h
+        copy /Y .\src\extras\raygui.h .\build\${{ env.RELEASE_NAME }}\include\raygui.h
         copy /Y .\README.md .\build\${{ env.RELEASE_NAME }}\README.md
         copy /Y .\LICENSE .\build\${{ env.RELEASE_NAME }}\LICENSE
         cd build