Update 0-welcome.yml

.github/workflows/0-welcome.yml

@@ -1,10 +1,22 @@
-name: Post welcome comment
+name: Step 0, Welcome
+
+# This step triggers after the learner creates a new repository from the template.
+# This workflow updates from step 0 to step 1.
+
+# This will run every time we create push a commit to `main`.
+# Reference: https://docs.github.com/en/actions/learn-github-actions/events-that-trigger-workflows
 on:
-  pull_request:
-    types: [opened]
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+
+# Reference: https://docs.github.com/en/actions/security-guides/automatic-token-authentication
 permissions:
-  pull-requests: write
-#ciao
+  # Need `contents: read` to checkout the repository.
+  # Need `contents: write` to update the step metadata.
+  contents: write
+
 jobs:
   # Get the current step to only run the main job when the learner is on the same step.
   get_current_step: