feat: add release workflow

This commit introduces a new GitHub Actions workflow for releases.
The workflow triggers on any tag push and sets up a Deno environment
to run the 'changelogithub' script. It has write permissions to the
repository contents.

.github/workflows/release.yaml

@@ -0,0 +1,26 @@
+name: release
+
+env:
+  DENO_VERSION: 1.x
+
+on:
+  push:
+    tags:
+      - '*'
+
+permissions:
+  contents: write
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: denoland/setup-deno@v1
+        with:
+          deno-version: ${{ env.DENO_VERSION }}
+      - run: deno run -A npm:changelogithub
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}