Updated outdated Docs "Getting Started" > "Create a New Monorepo" (#6786)
### Description
When going through the ["Getting Started > Create a New
Monorepo"](https://turbo.build/repo/docs/getting-started/create-new)
documentation I noticed it being outdated compared to the code I got
from `npx create-turbo@latest`.
I just went through the docs step by step and updated what I saw. Some
parts where more outdated than others, so I had to get my hands a bit
dirty to make it make sense 😇
I'm not the best typist in the world, so I would appreciate it if
someone could read through and make sure it's tight enough for the Turbo
Docs 😎
### Testing Instructions
- [x] Check spelling
- [x] Check grammar
- [x] Validate that new documentation is correct
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Co-authored-by: Anthony Shew <anthony.shew@vercel.com>
NOTE: Anthony is aware that docs lints are failing. He is working on getting them fixed.