Development Stage for new DIPs

[Mike Parker]

I would like to remind everyone to please read the procedures 
document regarding the development stage for a new DIP [1] before 
submitting one. DIPs *should not be developed in the PR queue*. 
Doing so has the potential to result in a long thread of comments 
on minor details before we're ready to begin the Draft review in 
the same thread.

New DIPs should be developed on a branch in your fork of the DIP 
repository and only submitted as a pull request when you are 
satisfied that the DIP is ready to begin the Draft Review. Think 
of it this way -- if it isn't in a state in which you would 
submit it to an editor as a first draft for editing, then it 
isn't ready for draft review.

[1] 
https://github.com/dlang/DIPs/blob/master/PROCEDURE.md#development-stage