refactor: reflect renamed default branch

site.Params.edit_page.repo_branch will now also default to `main` if unset.

.github/workflows/codeql-analysis.yml

@@ -13,10 +13,10 @@ name: "CodeQL"
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
     # The branches below must be a subset of the branches above
-    branches: [ master ]
+    branches: [ main ]
   schedule:
     - cron: '27 23 * * 5'