docs: note type enhancements breaking change

Author: dummdidumm

documentation/docs/05-misc/04-v4-migration-guide.md

@@ -157,3 +157,4 @@ The order in which preprocessors are applied has changed. Now, preprocessors are
 - `derived` will now throw an error on falsy values instead of stores passed to it. ([#7947](https://github.com/sveltejs/svelte/issues/7947))
 - type definitions for `svelte/internal` were removed to further discourage usage of those internal methods which are not public API. Most of these will likely change for Svelte 5
 - Removal of DOM nodes is now batched which slightly changes its order, which might affect the order of events fired if you're using a MutationObserver on these elements ([#8763](https://github.com/sveltejs/svelte/pull/8763))
+- if you enhanced the global typings through the `svelte.JSX` namespace before, you need to migrate this to use the `svelteHTML` namespace. Similarly if you used the `svelte.JSX` namespace to use type definitions from it, you need to migrate those to use the types from `svelte/elements` instead. You can find more information about what to do [here](https://github.com/sveltejs/language-tools/blob/master/docs/preprocessors/typescript.md#im-getting-deprecation-warnings-for-sveltejsx--i-want-to-migrate-to-the-new-typings)