docs(prisma): update prisma getting started guide

[mhartington]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/docs.nestjs.com/blob/master/CONTRIBUTING.md

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Docs
• Other... Please describe:

What is the current behavior?

The docs for using primsa are slight out of date for the upcoming Prisam 7 release.
Issue Number: N/A

What is the new behavior?

This updates the docs to match the new changes for the upcoming release

Does this PR introduce a breaking change?

• Yes
• No

Other information

These changes only come into effect with Prisma 7, which isn't released just yet, so please hold until the release is out 🙂

[kamilmysliwiec]

hey buddy, it's been a while. hope you're doing great!

lgtm, let's wait till v7 release then

[mhartington]

@kamilmysliwiec Prisam 7 is out! This can be merged now.

Hope you're doing well my friend!

[kamilmysliwiec]

LGTM