auto release create

.github/workflows/release.yaml

+name: Create Release
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: get release info
+        id: release_info
+        run: |
+          version="$(awk '/^## / { print tolower($2) }' CHANGELOG.md | head -1)"
+          changelog="$(sed -e "1,/^## ${version}/d" -e "/^## /,\$d" CHANGELOG.md)"
+          changelog="${changelog//'%'/'%25'}"
+          changelog="${changelog//$'\n'/'%0A'}"
+          changelog="${changelog//$'\r'/'%0D'}"
+          echo "::set-output name=version::$version"
+          echo "::set-output name=changelog::$changelog"
+
+      - name: create release
+        if: github.event_name == 'push' && github.ref == 'refs/heads/main' && steps.release_info.outputs.version != 'unreleased'
+        uses: actions/create-release@v1
+        id: create_release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ steps.release_info.outputs.version }}
+          release_name: Release ${{ steps.release_info.outputs.version }}
+          body: ${{ steps.release_info.outputs.changelog }}