ci: add template-sync (#416)

Author: nullishamy

.github/template-sync.yml

@@ -0,0 +1,12 @@
+dependents:
+  - "bot-boilerplate"
+
+files:
+  - ".gitignore"
+
+  # Do not sync the workflow files
+  - "!.github/workflows/template-sync.yml"
+  - "!.github/template-sync.yml"
+
+  # Do not sync dependabot config
+  - "!.github/dependabot.yml"

.github/workflows/template-sync.yml

@@ -0,0 +1,21 @@
+name: Template sync
+
+on:
+  workflow_dispatch:
+  workflow_run: # setup this workflow as a dependency of others
+    workflows: [ test ] # don't sync template unless tests and other important workflows have passed
+
+jobs:
+  template-sync:
+    timeout-minutes: 20
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ahmadnassri/action-workflow-run-wait@v1 # wait for workflow_run to be successful
+      - uses: ahmadnassri/action-workflow-queue@v1 # avoid conflicts, by running this template one at a time
+      - uses: ahmadnassri/action-template-repository-sync@v1
+        with:
+          github-token: ${{ secrets.GH_TOKEN }}
+          dry-run: true # Dry run for now