how-to-deploy.md

These docs are intendended to replace both docs.zed.dev and introduce people to how to build Zed from source.

1. cd docs from repo root
2. Install the vercel cli if you haven't already
   • pnpm i -g vercel
3. vercel to deploy if you already have the project linked
4. Otherwise, vercel login and vercel to link
   • Choose Zed Industries as the team, then zed-app-docs as the project

Someone can write a script for this when they have time.