clarify that "build & test everything" Grunt task requires Jekyll

Refs #13131.

diff --git a/docs/_includes/getting-started/grunt.html b/docs/_includes/getting-started/grunt.html
index f9f131087f43a2197318b2ae285b2dbff0b8eaa1..e5d4121eb009c23d77c41c79986aa55784155bc9 100644 (file)
--- a/docs/_includes/getting-started/grunt.html
+++ b/docs/_includes/getting-started/grunt.html
@@ -28,7 +28,7 @@
   <p>Builds and tests CSS, JavaScript, and other assets which are used when running the documentation locally via <code>jekyll serve</code>.</p>
 
   <h3><code>grunt</code> (Build absolutely everything and run tests)</h3>
-  <p>Compiles and minifies CSS and JavaScript, builds the documentation website, runs the HTML5 validator against the docs, regenerates the Customizer assets, and more. Usually only necessary if you're hacking on Bootstrap itself.</p>
+  <p>Compiles and minifies CSS and JavaScript, builds the documentation website, runs the HTML5 validator against the docs, regenerates the Customizer assets, and more. Requires <a href="http://jekyllrb.com/docs/installation/">Jekyll</a>. Usually only necessary if you're hacking on Bootstrap itself.</p>
 
   <h2 id="grunt-troubleshooting">Troubleshooting</h2>
   <p>Should you encounter problems with installing dependencies or running Grunt commands, first delete the <code>/node_modules/</code> directory generated by npm. Then, rerun <code>npm install</code>.</p>