[docs] Add @sjsf/sveltekit migration guide

Author: x0k

apps/docs/src/content/docs/migration-guides/current.mdx

@@ -4,6 +4,8 @@ sidebar:
   order: 0
 ---
 
+### @sjsf/form
+
 - Replace `<FormContent bind:value={form.formValue} />` with `<Content {form} />` from `@sjsf/form` package
 
 - Replace `SimpleForm` with `RawForm` from `@sjsf/form` package
@@ -20,8 +22,19 @@ sidebar:
 - Replace `import { omitExtraData2 } from "@sjsf/form/legacy-omit-extra-data"`
   with `import { omitExtraData } from "@sjsf/form/omit-extra-data"`
 
+### @sjsf/sveltekit
+
+- Upgrade SvelteKit package at least up to `2.12.0`
+
+- Migrate from `meta` and `useSvelteKitForm` to `createMeta`, `createSvelteKitRequest` and `createSvelteKitForm`
+  - In simple cases you may use only `createMeta` and `SvelteKitForm` component
+
+- Migrate from `validateForm` to `validateForm2` (support async validators)
+
 ## 1.8.0
 
+### @sjsf/form
+
 - Replace `useForm2` with `createForm3`
 
 - If custom form is used it should call `setFormContext(form.context)`