Merge pull request alphagov#307 from alphagov/ldeb-rename-default-branch-to-main

Rename default branch to 'main'

Author: lfdebrux

.github/workflows/publish.yaml

@@ -3,7 +3,7 @@ name: Publish
 on:
   push:
     branches:
-      - master
+      - main
   workflow_dispatch:
 
 concurrency: rubygems