Add .exclude() example to JS Guide

Added example of Query.exclude() in `js/queries.md`
Closes parse-community#632

_includes/js/queries.md

@@ -57,7 +57,7 @@ You can skip the first results by setting `skip`. In the old Parse hosted backen
 query.skip(10); // skip the first 10 results
 ```
 
-If you want to know the total number of rows in a table satisfying your query, for  e.g. pagination purposes - you can use `withCount`. 
+If you want to know the total number of rows in a table satisfying your query, for  e.g. pagination purposes - you can use `withCount`.
 
 **Note:** Enabling this flag will change the structure of response, see the example below.
 
@@ -176,6 +176,18 @@ query.find().then(function(results) {
 });
 ```
 
+Similarly, use `exclude` to remove undesired fields while retrieving the rest:
+
+```javascript
+var GameScore = Parse.Object.extend("GameScore");
+var query = new Parse.Query(GameScore);
+query.exclude("playerName");
+query.find().then(function(results) {
+  // Now each result will have all fields except `playerName`
+});
+```
+
+
 The remaining fields can be fetched later by calling `fetch` on the returned objects:
 
 ```javascript