Improve Installation Instructions

[meg-ray]

Create and link to a version of installation instructions for a complete beginner (ie. someone who has never done a local install before). We anticipate having contributors that are more education content-focused. This will help make the project more inclusive for those contributors.

[birdcar]

I'm going to work on this during the mentored sprints, and will ping you in Discord with some clarifying questions @meg-ray 🙇🏽