fix(ofm): allow wikilink alias to be empty (#1984)

This is in line with Obsidian's behavior.

quartz/plugins/transformers/ofm.ts

@@ -113,9 +113,9 @@ export const arrowRegex = new RegExp(/(-{1,2}>|={1,2}>|<-{1,2}|<={1,2})/g)
 // \[\[               -> open brace
 // ([^\[\]\|\#]+)     -> one or more non-special characters ([,],|, or #) (name)
 // (#[^\[\]\|\#]+)?   -> # then one or more non-special characters (heading link)
-// (\\?\|[^\[\]\#]+)? -> optional escape \ then | then one or more non-special characters (alias)
+// (\\?\|[^\[\]\#]+)? -> optional escape \ then | then zero or more non-special characters (alias)
 export const wikilinkRegex = new RegExp(
-  /!?\[\[([^\[\]\|\#\\]+)?(#+[^\[\]\|\#\\]+)?(\\?\|[^\[\]\#]+)?\]\]/g,
+  /!?\[\[([^\[\]\|\#\\]+)?(#+[^\[\]\|\#\\]+)?(\\?\|[^\[\]\#]*)?\]\]/g,
 )
 
 // ^\|([^\n])+\|\n(\|) -> matches the header row