Add source code bundle creation workflow

.forgejo/workflows/make-bundle.yaml

@@ -0,0 +1,23 @@
+name: Bundle
+run-name: Create a bundle for the project's source code
+on: [push]
+
+jobs:
+  make-bundle:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+          ref: main
+          fetch-depth: 0
+      - name: Upload source code
+        uses: actions/upload-artifact@v4
+        with:
+          name: source_archive
+          path: **
+          compression-level: 9
+          overwrite: true
+          include-hidden-files: true
+          if-no-files-found: error