In `mkd_document` I need to null terminate the buffer if it's not already null terminated. (a little bit of cosmetic sugar; it's supposed to be an arbitrary buffer of size bytes, but in reality none of those bytes will be 0, so people can use it as a C string.   If I explicitly null terminate it, there will be fewer surprises.)
In `mkd_document` I need to null terminate the buffer if it's not already null terminated.
(a little bit of cosmetic sugar; it's supposed to be an arbitrary buffer of
size bytes, but in reality none of those bytes will be 0, so people can use
it as a C string.   If I explicitly null terminate it, there will be fewer
surprises.)

OliverLetterer/discount,gm2bv/discount,davidfstr/discount,davidfstr/discount,OliverLetterer/discount,binki/discount,davidfstr/discount,gm2bv/discount,binki/discount,binki/discount,davidfstr/discount,binki/discount,binki/discount,gm2bv/discount,gm2bv/discount,OliverLetterer/discount