minor #17337 Mentioning svelte as a valid loader override type (weaverryan)

This PR was submitted for the 6.1 branch but it was merged into the 4.4 branch instead.

Discussion
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Mentioning svelte as a valid loader override type

Hi!

Minor tweak for symfony/webpack-encore#781

We could also document svelte itself, though there is also a proposed UX svelte component which, if merged, would be an even better option (and it would leverage this new feature in Encore).

Cheers!

Commits
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7f3a21d Mentioning svelte as aa valid loader override type

Author: javiereguiluz

frontend/encore/advanced-config.rst

@@ -230,6 +230,7 @@ The following loaders are configurable with ``configureLoaderRule()``:
   - ``sass`` (alias ``scss``)
   - ``less``
   - ``stylus``
+  - ``svelte``
   - ``vue``
   - ``eslint``
   - ``typescript`` (alias ``ts``)