Make adding a new version easier

[Witixin1512]

Adding a new version on the docs is something menial that should be made easier.

A non exhaustive things that would help doing this include:

• Have crafttweakerbot create the docs/$VERSION folder, with almost all files being copy pasted. The docs.json would probably be kept and have the Mods object be cleaned.
• An index of non auto generated pages that are prone to being updated (such as this one)
• Perhaps add a small changelog explaining classes scripters should be looking out for?