docs: added documentation for toast component changes (#7141)

* docs: added documentation for toast component changes

* added redirect from use-toast docs to upgrade guide

* remove unused file

* content linting fixes

* update UI package version

* updated ui preset

* fix upgrade guides main page

www/apps/ui/src/content/docs/hooks/use-toast.mdx

@@ -1,30 +0,0 @@
----
-title: "useToast"
-description: ""
-component: true
----
-
-
-This hook is used to display and manage toasts. To learn how to make it usable and to see some examples, please check the [Toast component page](/components/toast).
-
-```tsx
-import { useToast } from "@medusajs/ui"
-```
-
-## API Reference
-
----
-
-### Call Signature
-
-`useToast()`
-
-### useToast return
-
-<HookValues hook="useToast" />
-
-### ToasterToast
-
-Important type used when pushing or retrieving toasts. This extends the [Radix UI Toast Root](https://www.radix-ui.com/primitives/docs/components/toast#root) primitive type.
-
-<HookValues hook="ToasterToast" />