#310 Update wikilink regex to ignore empty brackets

Author: dullage

client/components/toastui/extendedAutolinks.js

@@ -76,7 +76,7 @@ export function parseUrlLink(source) {
 // end of raw toast-ui source
 
 function parseWikiLink(source) {
-  const matched = source.matchAll(/\[\[(.*?)\]\]/g);
+  const matched = source.matchAll(/\[\[\s*(\S(?:[^\[\]]*?\S)?)\s*\]\]/g);
   if (matched) {
     return Array.from(matched).map((match) => {
       const text = match[1];