Documentation Improvement Initiative

[Panke]

On Monday, 17 February 2020 at 12:16:26 UTC, Mike Parker wrote:
> If you feel the urge to wax philosophical on something you see 
> here, please start a new thread and do all the philosophical 
> waxing you want there. Let's keep this one focused on listing 
> specific documentation issues. Do feel free to expand on any 
> post here with information you think is relevant.
>
> Thanks!

A timeline of current language changes would be nice. What is 
currently deprecated and when will it be removed, what can be 
found under `dmd -preview=?` and when it will be part of the 
language or if it is just under consideration.