update prisma setup for workspaces

[Entkenntnis]

Where should we store our env strings, in root or in app?

also update readme

[elbotho]

Where should we store our env strings, in root or in app?

so far I did not put any .env files into the root and I guess until we don't share them across packages or apps it does not really matter.

[Entkenntnis]

Make it compile:

yarn build:prisma in root (no database string necessary)

[Entkenntnis]

next.js env:

apps/web/.env.local

[Entkenntnis]

• yarn prisma studio, yarn prisma db pull, yarn prisma db push should preferably use the same env file. only way seems like using custom scripts: https://www.prisma.io/docs/guides/development-environment/environment-variables/using-multiple-env-files

adding scripts would help anyways (and alias to root)