docs(tools): fix import statement in the example

Closes #5605

TOOLS_JS.md

@@ -14,7 +14,7 @@ Ctrl + Shift + j.
 By default the debug tools are disabled. You can enable debug tools as follows:
 
 ```typescript
-import {enableDebugTools} 'angular2/platform/browser';
+import {enableDebugTools} from 'angular2/platform/browser';
 
 bootstrap(Application).then((appRef) => {
   enableDebugTools(appRef);