adds publishing workflow

.github/workflows/publish.yml

@@ -0,0 +1,41 @@
+name: Publish
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby:
+          - '3.0'
+          - '3.1'
+          - '3.2'
+          - '3.3'
+
+    permissions:
+      contents: write # Required for `rake release` to push the release tag
+      id-token: write # Required for trusted publishing
+      packages: write # Required for publishing to GitHub Package Registry
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+
+      - name: Publish to GitHub Packages
+        env:
+          GEM_HOST_API_KEY: "Bearer ${{ secrets.GITHUB_TOKEN }}"
+          OWNER: ${{ github.repository_owner }}
+        run: |
+          mkdir -pv $HOME/.gem
+          touch $HOME/.gem/credentials
+          chmod 0600 $HOME/.gem/credentials
+          printf -- "---\n:github: ${GEM_HOST_API_KEY}\n" > $HOME/.gem/credentials
+          gem build *.gemspec
+          gem push --KEY github --host https://rubygems.pkg.github.com/${OWNER} *.gem

Gemfile.lock

@@ -63,6 +63,7 @@ GEM
     unicode-display_width (2.5.0)
 
 PLATFORMS
+  x86_64-darwin-21
   x86_64-linux
 
 DEPENDENCIES