Publish to RubyGems via GitHub actions.

.github/workflows/release.yaml

@@ -0,0 +1,18 @@
+name: Release Gem
+
+jobs:
+  release:
+    name: Release new version of ConfigSL
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+      contents: write
+    steps:
+      - run: echo "Releasing configsl-${{ github.ref }}"
+      - uses: actions/checkout@v4
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+#      - name: Push to rubygems
+#        uses: rubygems/release-gem@v1

README.md

@@ -1,4 +1,4 @@
-# ConfigSL [![Coverage Status][badge-coverage]][coverage]
+# ConfigSL [![Gem Version](https://badge.fury.io/rb/configsl.svg)](https://badge.fury.io/rb/configsl) [![Coverage Status][badge-coverage]][coverage]
 
 ConfigSL is a simple Domain-Specific Language (DSL) module for configuration.
 It is designed to provide a declarative way to define configuration, with as few