Add a comment as a reminder

Author: andylolz

.github/workflows/build.yml

@@ -5,7 +5,7 @@ on:
       - dev
   schedule:
     - cron: '0 1 * * *'
-  workflow_dispatch:
+  workflow_dispatch:  # for triggering builds manually
 jobs:
   generate_stats:
     runs-on: ubuntu-latest