show source view (plain=1) when navigating to edit page for page in AsciiDoc Lang docs

Author: mojavelinux

antora-playbook.yml

@@ -26,7 +26,7 @@ content:
   - url: https://gitlab.eclipse.org/eclipse/asciidoc-lang/asciidoc-lang.git
     branches: main
     start_path: docs
-    edit_url: '{web_url}/-/blob/{refname}/{path}'
+    edit_url: '{web_url}/-/blob/{refname}/{path}?plain=1'
   - url: https://github.com/asciidoctor/asciidoctor
     branches: v2.0.x
     start_path: docs