chore: Add link to supabase-kt repo in prep to archive the repo. (#15)

* Add link to supabase-kt repo

* make the message more descriptive

* Update README.md

Co-authored-by: Tyler <18113850+dshukertjr@users.noreply.github.com>

---------

Co-authored-by: Kevin Grüneberg <k.grueneberg1994@gmail.com>

README.md

@@ -1,5 +1,8 @@
 # Kotlin Client for PostgREST
 
+> **Warning**
+> This repository is archived. Use [supabase-kt](https://github.com/supabase-community/supabase-kt) instead to use Supabase in your Kotlin projects.
+
 Kotlin JVM client for [PostgREST](https://postgrest.org/)
 
 ![Java CI with Gradle](https://img.shields.io/github/workflow/status/supabase/postgrest-kt/Java%20CI%20with%20Gradle?label=BUILD&style=for-the-badge)
@@ -218,4 +221,4 @@ val postgrestClient = PostgrestClient(
     httpClient = customHttpClient(),
     jsonConverter = customConverter()
 )
-```
+```