[spec] Numbered chapters

[Dibyendu Majumdar]

On Wednesday, 15 May 2019 at 15:22:53 UTC, Andrei Alexandrescu 
wrote:
> I think some things ought indeed to be reordered. Not sure 
> about moving the grammar to the appendix. Larger point is - do 
> you really want your first contribution to be a major revamp? 
> Why? No need to mark your territory. There's so many good 
> things to do there that can be done quickly while learning the 
> ropes.

Also to clarify - not trying to mark territory or anything like 
that. Just want to help D in a concrete way - I do not use D so 
nothing to prove.