Try and fix internal directory structure

Author: electricbrass

.github/workflows/macos.yml

@@ -31,9 +31,9 @@ jobs:
     - name: Create DMG
       run: |
         brew install create-dmg
-        mkdir -p build/artifact && cd build
-        cp -aR "client/odamex.app" "server/odasrv" "odalaunch/odalaunch.app" "../config-samples" "../MAINTAINERS" "../CHANGELOG" "../README" "../LICENSE" artifact/
-        create-dmg odamex.dmg ./artifact --background ../media/macinstaller-background.png
+        mkdir -p build/dmg/Odamex && cd build
+        cp -aR "client/odamex.app" "server/odasrv" "odalaunch/odalaunch.app" "../config-samples" "../MAINTAINERS" "../CHANGELOG" "../README" "../LICENSE" dmg/Odamex/
+        create-dmg odamex.dmg ./dmg --background ../media/macinstaller-background.png
     - name: Upload DMG
       uses: actions/upload-artifact@v4
       with: