Clarify "Starting as a Contributor" document

[Dukc]

On Sunday, 10 December 2017 at 08:18:17 UTC, Ali Çehreli wrote:
> This page is very good:
>
>   https://wiki.dlang.org/Starting_as_a_Contributor
>
> I need clarifications

Another oddity: Someone has apparently made DRuntime build to use 
../dmd/generated/windows/32/dmd instead of the "system" dmd 
recently. Perhaps the idea here is that I do not have to go 
replacing my system dmd anymore.

But the problem is that when I build dmd, for some reason, the 
build file deletes that generated dmd at the end. Can be resolved 
by moving the dmd manually to that directory, but that is not 
explained at the web page. Should we tweak dmd to build into the 
generated directory instead of working directory, or tweak 
DRuntime to use ../dmd/src/dmd instead? Or am I missing something?