Add release.yml to create release on tag push

.github/workflows/release.yml

@@ -0,0 +1,26 @@
+name: create release
+on:
+  push:
+    tags:
+      - "v*"
+jobs:
+  release:
+    name: Create release
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Generate release notes
+        run: |
+          cat >release_notes.md <<EOF
+          See [CHANGELOG.md](https://github.com/zmwangx/rust-ffmpeg/blob/${GITHUB_REF##*/}/CHANGELOG.md) for changes.
+          EOF
+      - name: Create release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          body_path: release_notes.md
+          draft: false
+          prerelease: false