[Docs] Update WSL instructions + fix broken links

[charlesBochet]

Small PR on docs to:

• grant 'twenty' postgres user database creation rights (this is needed for prisma to compute new migration as it is creating a shadow database: https://www.prisma.io/docs/concepts/components/prisma-migrate/shadow-database
• fix link to Yarn Install on WSL setup page
• fix broken link on getting-started page

[ergomake]

Hi 👋

Here's a preview environment 🚀

https://front-twentyhq-twenty-1204.env.ergomake.link

Environment Summary 📑

Container	Source	URL
front	Dockerfile	https://front-twentyhq-twenty-1204.env.ergomake.link
server	Dockerfile	https://server-twentyhq-twenty-1204.env.ergomake.link
postgres	Dockerfile	[not exposed - internal service]

Here are your environment's logs.

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