Add basic setup guides for fansubbing

[LightArrowsEXE]

The subtitling part of this guide is pretty barren now, so I'd like to begin by writing some guides on how to set up a basic environment for members to access and use. This will include stuff like how to use an FTP and/or GitHub, and how to use SubKt, among other things.

• Create a tutorial explaining how to make, maintain, and use an FTP server/client (Add guides for using an FTP and GitHub setup in a fansub group #65)
• Create a tutorial explaining how to make, maintain, and use a GitHub repository/client (Add guides for using an FTP and GitHub setup in a fansub group #65)
• Create a tutorial explaining how to use SubKt, as well as how to write a build script

[FichteFoll]

As I mentioned in #65, I'm not sure how much detail we'd want from a page on setting up and configuring an FTP server.

For the git side, I'd certainly be interested in documenting the various advanved tricks for working with ASS files in a repo that @Myaamori has been developing, most notably a filter for Aegisub Project Garbage and a custom merge strategy that handles intra-line changes (timing vs text). But that's not necessary for the first version.