Add information on login into the supabase-cli

# Improve documentation ## Link https://supabase.com/docs/reference/javascript/typescript-support#generating-typescript-types ## Describe the problem If you follow the docs step by step, you'll reach the point where it sais: You can use the Supabase CLI to [generate the types](https://supabase.com/docs/reference/cli/supabase-gen-types). You can also generate the types [from the dashboard](https://supabase.com/dashboard/project/_/api?page=tables-intro). Here if you just run it like that it will fail because you're not authenticated in the CLI. ## Describe the improvement There is no mention on running `supabase login` anywhere, I mean it is kinda obvious but still took me a few minutes to figure out. I think a little hint in the docs would be nice