Description lists

[kabajau]

Is your feature request related to a problem? Please describe.
Nextcloud markdown doesn't have a syntax for description lists.

Describe the solution you'd like
Add support for a description list syntax, such as the one implemented by HedgeDoc:

Term A

: Description of term A.

Term B
: Description of Term B.


Term C
: First description of term C.
: Second description of term C.

Term D
: First description of term D.

: Second description of term D.

Up to one empty line between a title and a corresponding description should be allowed (as shown in Term A).

At least one empty line between the last description of one title and the next title should be required.

One or more empty lines between two descriptions corresponding to the same title should be allowed (as shown in Term D).

The above markdown should be equivalent to the following HTML:

<dl>
    <dt>Term A</dt>
    <dd>Description of term A.</dd>
    <dt>Term B</dt>
    <dd>Description of term B.</dd>
    <dt>Term C</dt>
    <dd>First description of term C.</dd>
    <dd>Second description of term C.</dd>
    <dt>Term D</dt>
    <dd>First description of term D.</dd>
    <dd>Second description of term D.</dd>
<dl>

Describe alternatives you've considered
Not use description lists, but that's not really an alternative.