Include root directory that matches file name

Github's generated release files include the root directory when publishing releases. Make sure this action also has this characteristic.

Author: braiam

.github/workflows/publish-header.yml

@@ -11,8 +11,9 @@ jobs:
     - uses: actions/checkout@v3
     - name: bundle header
       run: |
-        mv amf/public/include AMF
-        tar czf AMF-headers.tar.gz AMF/
+        mkdir amf-headers
+        mv amf/public/include amf-headers/AMF
+        tar czf AMF-headers.tar.gz amf-headers/
     - name: Release
       uses: softprops/action-gh-release@v1
       if: startsWith(github.ref, 'refs/tags/')