Adding Markdown to Ddoc

[John Gabriele]

On Tuesday, 12 December 2017 at 15:59:42 UTC, John Gabriele wrote:
> On Monday, 11 December 2017 at 00:54:00 UTC, Walter Bright 
> wrote:
>>
>> I have a more pragmatic definition of a standard:
>>
>> 1. Products that implement it say they adhere to it and defer 
>> to it as the authority on correct behavior.
>>
>> 2. There's more than one such product.
>>
>> 3. There's more products adhering to that standard than some 
>> other competing standard.
>>
>> So far as I know, commonmarkdown satisfies zero of those.
>
> Looks like Stack Exchange is working on standardizing on 
> CommonMark:
> <https://meta.stackexchange.com/questions/238957/will-commonmark-be-adopted-for-se/258587#258587>

Rust is as well: <https://github.com/rust-lang/rust/issues/44229>.