Add forking guidelines

[dffdff2423]

Adds a page outlining forking guidelines and best practices. A large amount of content in this is derived from https://gist.github.com/moonheart08/2d3945faf3cf691437e1e1fa0e922420. I have permission from the author to use their work in this PR. It also incorporates some of my own advice gained from working on Cosmatic Drift.

[Jezithyr]

This looks great so far! But it's missing a section on licensing and attribution. We should at the very least give people a basic idea of what copyright is/does, since not everyone is familiar with it and there are a ton of common misconceptions that can get you into trouble.
I'll write something up and run it by a couple of my industry connections to make sure that it's accurate to how copyright works. Licensing stuff shouldn't be a problem for most forks since they'll likely just going to keep the MIT license but it's still a good idea to make sure people are aware of misconceptions and common pitfalls.

Actually, I might just make a separate doc on copyright/licensing and then just include a brief summary in the forking guidelines. Great work on this :)

[Jezithyr]

We should add a short section here summarizing the basics of copyright/licensing to help prevent people from falling into common pitfalls. I'll write something up this week unless you'd like to write something up and I can look it over :)
Once we've got that, this will be good to merge!

[dffdff2423]

I actually had some something small about the AGPL (most forks are not using it correctly, they are incorrectly relicensing wizden code to the AGPL when merging upstream), but opted not to include it because I did not want to start shit due to how much of a hot topic that is in ss14. We could link https://choosealicense.com/ which is written by github and I assume vetted by their lawers. I think that this document should take as much of a neutral perspective in terms of which license to choose because that is a highly personal choice.

[dffdff2423]

I think one of the main issues with the above site is it encourages using the GPL over the AGPL for a copyleft license which is sound advice for most projects, but will probably not do what they intend for a ss14 fork.

[dffdff2423]

I actually ended up writing a short copyright gide. Let me know if you want me to change anything. My goal was to take as neutral of a stance as possible while giving a basic explanation of all of the licenses that I am aware of ss14 forks using. If people don't understand the basics of software copyright I think they should be referred elsewhere given it is such a complex topic and most (all?) of the people who work on ss14 are not experts in it and such should not be writing a guide on copyright.