Add a github action to publish gem to Rubygem

.github/workflows/gem-push.yml

@@ -0,0 +1,46 @@
+name: Push to RubyGems
+
+on: workflow_dispatch
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby-version: ["3.3", "3.2", "3.1", "3.0"]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@359bebbc29cbe6c87da6bc9ea3bc930432750108
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+      - name: Install dependencies
+        run: bundle install
+      - name: Run tests
+        run: bundle exec rspec
+
+  publish:
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@359bebbc29cbe6c87da6bc9ea3bc930432750108
+        with:
+          ruby-version: "3.1"
+
+      - name: Publish to RubyGems
+        run: |
+          mkdir -p $HOME/.gem
+          touch $HOME/.gem/credentials
+          chmod 0600 $HOME/.gem/credentials
+          printf -- "---\n:rubygems_api_key: ${GEM_HOST_API_KEY}\n" > $HOME/.gem/credentials
+          gem build *.gemspec
+          gem push *.gem
+        env:
+          GEM_HOST_API_KEY: "${{secrets.RUBYGEMS_API_KEY}}"