Add template and workflow to add review template to PRs (#19185)

* add review template and workflow

* use sha instead of version for action

* exclude template from check for private repo links

* Apply suggestions from code review

Co-authored-by: Emily Gould <4822039+emilyistoofunky@users.noreply.github.com>

Co-authored-by: Emily Gould <4822039+emilyistoofunky@users.noreply.github.com>

.github/workflows/add-review-template.yml

@@ -0,0 +1,36 @@
+name: Add review template
+
+# **What it does**: When a specific label is added to a PR, adds the contents of .github/review-template.md as a comment in the PR
+# **Why we have it**: To help Docs Content team members ensure that their PR is ready for review
+# **Who does it impact**: docs-internal maintainers and contributors
+
+on:
+  pull_request:
+    types:
+      - labeled
+
+jobs:
+  comment-that-approved:
+    name: Add review template
+    runs-on: ubuntu-latest
+    if: github.event.label.name == 'docs-content-ready-for-review' && github.repository == 'github/docs-internal'
+
+    steps:
+      - name: check out repo content
+        uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f
+
+      # Jump through some hoops to work with a multi-line file
+      - name: Store review template in variable
+        run: |
+          TEMPLATE=$(cat .github/workflows/review-template.md)
+          echo "TEMPLATE<<EOF" >> $GITHUB_ENV
+          echo "$TEMPLATE" >> $GITHUB_ENV
+          echo "EOF" >> $GITHUB_ENV
+
+      - name: Comment on the PR
+        run: |
+          gh pr comment $PR --body "$TEMPLATE"
+        env:
+          GITHUB_TOKEN: ${{secrets.DOCUBOT_FR_PROJECT_BOARD_WORKFLOWS_REPO_ORG_READ_SCOPES}}
+          PR: ${{ github.event.pull_request.html_url }}
+          TEMPLATE: ${{ env.TEMPLATE }}