Core: Update API doc to document `Prism.highlightAllUnder()`
diff --git a/extending.html b/extending.html
index 51bf777..a19777c 100644
--- a/extending.html
+++ b/extending.html
@@ -158,6 +158,24 @@
</dl>
</section>
+ <section id="highlight-all-under">
+ <h1><code>Prism.highlightAllUnder(element, async, callback)</code></h1>
+ <p>Fetches all the descendants of <code>element</code> that have a <code>.language-xxxx</code> class
+ and then calls <code>Prism.highlightElement()</code> on each one of them.</p>
+
+ <h2>Parameters</h2>
+ <dl>
+ <dt>element</dt>
+ <dd>The root element, whose descendants that have a <code>.language-xxxx</code> class will be highlighted.</dd>
+
+ <dt>async</dt>
+ <dd>Whether to use Web Workers to improve performance and avoid blocking the UI when highlighting very large chunks of code. False by default (<a href="faq.html#why-is-asynchronous-highlighting-disabled-by-default">why?</a>).</dd>
+
+ <dt>callback</dt>
+ <dd>An optional callback to be invoked after the highlighting is done. Mostly useful when <code>async</code> is true, since in that case, the highlighting is done asynchronously.</dd>
+ </dl>
+ </section>
+
<section id="highlight-element">
<h1><code>Prism.highlightElement(element, async, callback)</code></h1>
<p>Highlights the code inside a single element.</p>