docs: Add FAQ entry for common Vue problem

Closes shaka-project#3155

Change-Id: Ia8340796507ce4db37e29bd0d7c729cbb26b1325

docs/tutorials/faq.md

@@ -260,6 +260,20 @@ the {@link shaka.extern.ManifestConfiguration|`.manifest.disableVideo`} or
 configurations to signal that your content does not have a video or audio 
 stream.
 
+<hr>
+
+**Q:** How can I make Shaka Player work with Vue?
+
+**A:** Currently, Shaka Player does not support being made into a Vue reactive
+object. When Vue wraps an object in a reactive Proxy, it
+{@link https://v3.vuejs.org/guide/reactivity.html#proxied-objects|also wraps
+nested objects}. This results in Vue converting some of our internal values into
+Proxy objects, which causes failures at load-time.
+If you want to use Shaka Player in Vue, avoid making it into a reactive object;
+so don't declare it using a ref(), and if you put your player instance into a
+data() object, you can prefix the property name with "$" or "_" to make Vue not
+proxy them.
+
 [386]: https://github.com/google/shaka-player/issues/386#issuecomment-227898001
 [489]: https://github.com/google/shaka-player/issues/489#issuecomment-240466224
 [743]: https://github.com/google/shaka-player/issues/743