add: releaseタグ付けのgithub actionを追加

NetCommons3/NetCommons3#1619

.github/workflows/release.yml

@@ -0,0 +1,28 @@
+on:
+  push:
+    # Sequence of patterns matched against refs/tags
+    tags:
+      - '3*'
+
+name: Create Release
+
+jobs:
+  build:
+    name: Create Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # This token is provided by Actions, you do not need to create your own token
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          body: |
+            NetCommons ${{ github.ref }} released.
+          draft: false
+          prerelease: false