Fix broken search after pre-commit#512

If `type` equals the empty string, no type filter should be applied.

Closes pre-commit#520

assets/filter_repos.js

@@ -22,7 +22,7 @@
                     const hookId = repoHook.dataset.id.toLowerCase();
                     const hookTypes = repoHook.dataset.types.split(', ');
 
-                    if (hookId.includes(id) && hookTypes.includes(type)) {
+                    if (hookId.includes(id) && (type === '' || hookTypes.includes(type))) {
                         repoHook.hidden = false;
                         hasVisibleHooks = true;
                     } else {