Adding Markdown to Ddoc

[Sönke Ludwig]

Am 06.12.2017 um 12:34 schrieb Walter Bright:
> On 12/6/2017 1:33 AM, Sönke Ludwig wrote:
>> This is great news! While I don't have the time to work on this 
>> directly, I can offer vibe.d's Markdown module* (re-licensing as 
>> necessary): 
>> https://github.com/vibe-d/vibe.d/blob/master/textfilter/vibe/textfilter/markdown.d 
>>
>>
>> Markdown is a strange thing to parse in the classical way due to its 
>> original regex-cascade style of implementation/design, so it was kind 
>> of difficult to find representations that allow reasonably efficient 
>> and comprehensible processing.
>>
>> * There is also "dmarkdown", which is just a fork of the vibe.d code
> 
> Thanks! It's always great to be able to leverage existing code. But 
> you'll need to Boost license it!

No problem!