Docs Request: Add a “Local Development” guide covering env setup, common commands, and troubleshooting

[09-jigsaw]

What is the issue you are encountering with the docs?

Developers new to base/web may struggle to get the project running locally due to missing or unclear documentation around environment variables, required tooling, and the standard development workflow.

Without a dedicated local development guide, contributors often need to infer:

• required Node.js / package manager versions
• how to set up .env files and which variables are required
• which commands to run for dev, build, lint, and test
• common troubleshooting steps for typical setup failures

Links to Impacted Docs

No response

Describe the solution you'd like to see.

• Add a docs/local-development.md (or README section) that includes:
  • prerequisites (Node version, package manager, any required tools)
  • environment setup (.env example, required variables, where to obtain values)
  • common commands (dev, build, lint, test)
  • troubleshooting section for frequent issues
• Link this guide prominently from the main README.

Additional context

No response