Add link to Mozilla docs about events bubbling and capture phase

Fixes #2393

site/content/tutorial/05-events/03-event-modifiers/text.md

@@ -21,7 +21,7 @@ The full list of modifiers:
 * `preventDefault` — calls `event.preventDefault()` before running the handler. Useful for e.g. client-side form handling
 * `stopPropagation` — calls `event.stopPropagation()`, preventing the event reaching the next element
 * `passive` — improves scrolling performance on touch/wheel events (Svelte will add it automatically where it's safe to do so)
-* `capture` — fires the handler during the *capture* phase instead of the *bubbling* phase
+* `capture` — fires the handler during the *capture* phase instead of the *bubbling* phase ([MDN docs](https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Building_blocks/Events#Event_bubbling_and_capture))
 * `once` — remove the handler after the first time it runs
 
 You can chain modifiers together, e.g. `on:click|once|capture={...}`.