Add brackets to helper for automatically escaping selector string in FAQ. Fixes jquery#224.

Author: qnet-herwin

page/using-jquery-core/faq/how-do-i-select-an-element-by-an-id-that-has-characters-used-in-css-notation.md

@@ -26,7 +26,7 @@ The following function takes care of escaping these characters and places a "#"
 ```
 function jq( myid ) {
 
-  return "#" + myid.replace( /(:|\.)/g, "\\$1" );
+  return "#" + myid.replace( /(:|\.|\[|\])/g, "\\$1" );
 
 }
 ```
@@ -35,4 +35,4 @@ The function can be used like so:
 
 ```
 $( jq("some.id") )
-```
+```