migration docs

README.md

@@ -288,3 +288,16 @@ it's because of whitespsace sensitivity. For inline elements (`span`, `a`, etc)
 
 `prettier-plugin-svelte` v2 is compatible with Prettier v2 and incompatible with Prettier v3.
 `prettier-plugin-svelte` v3 is compatible with Prettier v3 and incompatible with lower Prettier versions.
+
+### How to migrate from version 2 to 3?
+
+Version 3 contains the following breaking changes:
+
+-   Whether or not empty elements/components should self-close is now left to the user - in other words, if you write `<div />` or `<Component />` that stays as is, and so does `<div></div>`/`<Component></Component>`. If `svelteStrictMode` is turned on, it will still only allow `<div></div>` notation for elements (but it will leave your components alone)
+-   `svelteAllowShorthand` now takes precedence over `svelteStrictMode`, which no longer has any effect on that behavior. Set `svelteAllowShorthand` to `false` to get back the v2 behavior
+-   Some deprecated `svelteSortOrder` options were removed, see the the options section above for which values are valid for that options
+
+Version 3 of this plugin requires Prettier version 3, it won't work with lower versions. Prettier version 3 contains some changes to how it loads plugins which may require you to adjust your configuration file:
+
+-   Prettier no longer searches for plugins in the directory automatically, you need to tell Prettier specifically which plugins to use. This means you need to add `"plugins": ["prettier-plugin-svelte"]` to your config if you haven't already. Also remove the deprecated option `pluginSearchDirs`. When invoking Prettier from the command line, you currently need to pass `--plugin prettier-plugin-svelte` in order to format Svelte files [due to a bug in Prettier](https://github.com/prettier/prettier/issues/15079)
+-   Prettier loads plugins from the plugin array differently. If you have used `require.resolve("prettier-plugin-svelte")` in your `.prettierrc.cjs` to tell Prettier where to find the plugin, you may need to remove that and just write `"prettier-plugin-svelte"` instead