Project Edit: Improve the documentation section UI

[heathermiller]

(Guillaume, don't worry about this one. This is book-keeping for me)

The little pseudo-DSL for specifying documentation is nice. Though the UI on the edit page is a bit confusing. It could maybe be clarified/streamlined so it makes a bit more intuitive sense off the bat.

[MasseGuillaume]

Maybe some live editing example.

Given a release and this documentation expression this is the output. The output changes on a key press.