Update readme with instructions for local dev

[nikfp]

As part of bringing people on board to help build this repo, a guide in the README.md explaining how to build the app and get it running locally will be required. From what I've been able to dig up so far, the following items will need to be clarified.

• Clarification of how the app interacts with Supabase and how Supabase should be configured to populate data, allow auth, etc.
  • Supabase might also have a way to extract an sql query that devs can run on their own instance to match the LBT schema.
  • Connecting and running pg_dump with the --schema-only flag should also be enough
  • Also need to address seed data if required.
• Quick explanation of how to set up a local .env file to pass Supabase credentials into the app
• Building and running the app locally
  • Address whether support should be included for alternate package managers or stick with strictly NPM
  • Make sure no global dependencies are expected on a dev's system - Typescript, Vite, etc.
• Address code quality expectations - formatting, linting, etc. (Can address most through config)
  • Should a check command be added to local scripts in package.json?

Also please comment with any items I'm missing and I'll add them to the list.

[rossrobino]

This would be great, would love to find a way to contribute

[waseem-medhat]

As someone willing to work on the HTML/CSS parts of the website, I would find it extremely convenient if the project can be configured (via an env variable maybe?) to use some mock data to render the (otherwise) dynamic content without having to call Supabase at all... Just a thought.