Guide for handling multiple developers

[itinerare]

Given that a decent portion of Lorekeeper's userbase isn't liable to be familiar with best practices in this regard, it's a good idea to add a guide of sorts outlining:

• How to approach collaboration/multiple developers
  • Handling it through a hosted repo external to the site, requiring code review, etc. including the what, how, and why of it, aimed at folks without a technical background
• Any other related material that would be worth covering?

If desired, please use this issue as a space to organize and coordinate updates.

[perappu]

Had someone once tell me "code reviews make sense, it's like how we have at least two people review MYOs to make sure it's correct" so there's an easy and understandable comparison to make for our community!