Fix invalid link matcher

_plugins/bidirectional_links_generator.rb

@@ -31,7 +31,7 @@ def generate(site)
       # pointing to non-existing pages, so let's turn them into disabled
       # links by greying them out and changing the cursor
       current_note.content = current_note.content.gsub(
-        /\[\[?(.*)\]\]/i, # match on the remaining double-bracket links
+        /\[\[(.*)\]\]/i, # match on the remaining double-bracket links
         <<~HTML.chomp     # replace with this HTML (\\1 is what was inside the brackets)
           <span title='There is no note that matches this title.' class='invalid-link'>
             <span class='invalid-link-brackets'>[[</span>