Docs: update watch task in CONTRIBUTING.md

Close gh-5331

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 79609486112b693379e4a8081751e7352c8e4377..552474a8dcf52673e976b8f5e1b3eb3237827897 100644 (file)
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -126,10 +126,10 @@ This will only run the "css" module tests. This will significantly speed up your
 
 #### Loading changes on the test page
 
-Rather than rebuilding jQuery with `grunt` every time you make a change, you can use the included `grunt watch` task to rebuild distribution files whenever a file is saved.
+Rather than rebuilding jQuery with `npm run build` every time you make a change, you can use the included watch task to rebuild distribution files whenever a file is saved.
 
 ```bash
-$ grunt watch
+$ npm start
 ```
 
 Alternatively, you can **load tests as ECMAScript modules** to avoid the need for rebuilding altogether.