add lowercase in regex

Playground/js/main.js

@@ -1073,7 +1073,7 @@ class Main {
             }
         }
         if (pgHash) {
-            var match = pgHash.match(/^(#[A-Z\d]*)(%23)([\d]+)$/);
+            var match = pgHash.match(/^(#[A-Za-z\d]*)(%23)([\d]+)$/);
             if (match){
                 pgHash = match[1]+'#'+match[3];
                 parent.location.hash = pgHash;