Add automatic public changelog entry publish

Copy the setup from our integration repositories to automatically create
a PR on the public changelog when we release a new version.

Closes #34

Author: tombruijn

.github/workflows/create_release_from_tag.yml

@@ -0,0 +1,61 @@
+name: "Create release from tag"
+
+on:
+  push:
+    tags:
+      - "v**"
+
+permissions:
+  contents: write
+  actions: write
+
+jobs:
+  release:
+    name: "Create release"
+    runs-on: ubuntu-latest
+    env:
+      PACKAGE_NAME: "Wrap"
+      CHANGELOG_CATEGORY: "Wrap"
+      CHANGELOG_LINK: "https://github.com/appsignal/appsignal-wrap/blob/main/CHANGELOG.md"
+    steps:
+      - name: Checkout repository at tag
+        uses: actions/checkout@v4
+        with:
+          ref: "${{ github.ref }}"
+
+      - name: Get tag name
+        run: |
+          echo "TAG_NAME=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
+
+      - name: Get changelog contents from tag
+        run: |
+          # Use sed to remove everything after "-----BEGIN PGP SIGNATURE-----" if it's present
+          # and also always remove the last line of the git show output
+          git show --format=oneline --no-color --no-patch "${{ env.TAG_NAME }}" \
+          | sed '1,3d' \
+          | sed '$d' \
+          | sed '/-----BEGIN PGP SIGNATURE-----/,$d' \
+          > CHANGELOG_TEXT.txt
+
+          echo "" >> CHANGELOG_TEXT.txt
+
+          TAG_NAME_FOR_LINK=$(echo "${{ env.TAG_NAME }}" | sed 's/^v//' | tr -d '.')
+          echo "View the [$PACKAGE_NAME ${{ env.TAG_NAME }} changelog]($CHANGELOG_LINK#$TAG_NAME_FOR_LINK) for more information." >> CHANGELOG_TEXT.txt
+
+      - name: Submit changelog entry
+        run: |
+          # Prepare JSON payload using jq to ensure proper escaping
+          payload=$(jq -n \
+            --arg title "$PACKAGE_NAME ${{ env.TAG_NAME }}" \
+            --arg category "$CHANGELOG_CATEGORY" \
+            --arg version "$(echo "${{ env.TAG_NAME }}" | sed 's/^v//')" \
+            --arg changelog "$(cat CHANGELOG_TEXT.txt)" \
+            --arg assignee "${{ github.actor }}" \
+            '{ref: "main", inputs: {title: $title, category: $category, version: $version, changelog: $changelog, assignee: $assignee}}')
+
+          curl -X POST \
+            -H "Authorization: token ${{ secrets.INTEGRATIONS_CHANGELOG_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            --fail-with-body \
+            https://api.github.com/repos/appsignal/appsignal-web/actions/workflows/create_integrations_changelog_entry.yml/dispatches \
+            -d "$payload"