Add export to other static site generator systems.

[dbriemann]

The idea is to have Glyph export a project for another static site generator like Hugo. This allows to utilize all the existing power of those generators without re-implementing things in Glyph.

I am not convinced here. This feature means that Glyph always has to follow changes in said generators and also adds complexity to the project. This feature was a suggestion and I will keep it here so others can give their opinion/input on it. For now it's just an idea.