Add instructions to set up dev environment

Add instructions on how to set up the project and the dev environment. Would be useful to have someone else do this since my environment has been around for a while, so not sure what you need to do from scratch. Also, I use Windows so it might be different for people on Mac or Linux. If we can add a script for some of these steps, that would be great as well:

- Windows specific: Setup autocrlf: `git config --global core.autocrlf false `
- Setup and force initialize `.env
- Getting tokens from Discord and Meetup (Meetup API is paid so not sure about this. Might be able to use their test token).
- Setting up test Discord servers and Meetup groups (Terraform might be helpful for creating the test servers"
- Downloading dependencies and run script