Finish deploy on Vercel Sanity link and template publishing

`https://vercel.com/new/clone?repository-url=https%3A%2F%2Fgithub.com%2Ffocusreactive%2Fcms-kit&project-name=sanity-cms-kit&repository-name=sanity-cms-kit&integration-ids=oac_hb2LITYajhRQ0i4QznmKH7gx&build-command=cd%20../../%20%26%26%20turbo%20run%20build%20--filter%3Dsanity&install-command=pnpm%20i&root-directory=apps/sanity&env=NEXT_PUBLIC_DOMAIN&envDescription=%5Bvercel-project-name%5D.vercel.app&envLink=https%3A%2F%2Fgithub.com%2Ffocusreactive%2Fcms-kit%2Fblob%2Fmain%2Fapps%2Fsanity%2F.env.local.example`

- [x] finalize vercel deploy link
- [x] add new instruction to read me
- [x] make sure docs covers new approach with direct deployment without **roll out script**
- [ ] ~~Show block with instruction when using "deploy on vercel button"~~

When people create project using "deploy on vercel" button, we don't populate database, therefore user sees an error when trying to preview the page. The error happens because there is no document for header/footer/page. Once corresponding documents are created, preview is correctly displayed.

show block with instructions how to approach new project

make sure user understand what is going on and what is expected from him