Switch to using pycmarkgfm lib for rendering.

[Humbedooh]

This would use the pycmarkgfm pip library instead of having to build and call the gfm C library. Should make things more portable.

[sebbASF]

Why use this and not cmarkgfm? Do we need task lists?

[sebbASF]

Note that the installation still requires the library to be built.
However this is done as part of the pip install process which makes it much easier.

The Dockerfile will need to be reworked; by the time requirements.txt is processed, the build tools have been dropped.

[sebbASF]

There are various references to LIBCMARKDIR in the code which need to be fixed before this can be deployed

[sebbASF]

AFAICT there are minimal differences in the generated output, at least for the main website.

There are some minor spacing and line-wrap differences between tags.

The only other difference I noticed is that URLs such as:

http://people.apache.org/%7Ecurcuru
are now rendered as
http://people.apache.org/~curcuru