Adding regex comments.

backend/src/api/explorer/nodes.api.ts

@@ -363,8 +363,8 @@ class NodesApi {
     try {
       const publicKeySearch = search.replace('%', '') + '%';
       const aliasSearch = search
-        .replace(/[-_.]/g, ' ')
-        .replace(/[^a-zA-Z0-9 ]/g, '')
+        .replace(/[-_.]/g, ' ') // Replace all -_. characters with empty space. Eg: "ln.nicehash" becomes "ln nicehash".  
+        .replace(/[^a-zA-Z0-9 ]/g, '') // Remove all special characters and keep just A to Z, 0 to 9.
         .split(' ')
         .filter(key => key.length)
         .map((search) => '+' + search + '*').join(' ');