doc: Markdown to man conversion

[petrasovaa]

In order to remove html files, we need to start converting manual pages from markdown. This PR includes the conversion script and some basic makefile modifications. The conversion script is far from perfect, it needs to be tested more and it does not support tables yet. Some nested elements don't work very well, because I (and AI) wrote just a simplified markdown parser. The parser relies on the currently enabled markdown linting rules.

I didn't remove the html built, that's probably a separate PR.

[susi]

Drive-by comment: Why build a custom thing when pandoc can do the work and more? At least this seems to me to be a more efficient way to acchieve the result? As a further benefit by adopting pandoc it can also output other formats such as HTML and PDF.

It does add a new dependancy, however, it is already well known and well-tested, and very modular.

[echoix]

Drive-by comment: Why build a custom thing when pandoc can do the work and more? At least this seems to me to be a more efficient way to acchieve the result? As a further benefit by adopting pandoc it can also output other formats such as HTML and PDF.

It does add a new dependancy, however, it is already well known and well-tested, and very modular.

If I'm not mistaken, pandoc was used to do the bulk of the conversion, but it wasn't perfect here, but with a custom Lua filter for code blocks it was better

[neteler]

pandoc was used to do the bulk of the conversion

Yes. The script is here:

• https://github.com/OSGeo/grass/blob/main/utils/grass_html2md.sh
• https://github.com/OSGeo/grass/blob/main/utils/pandoc_codeblock.lua

[petrasovaa]

pandoc was used to do the bulk of the conversion

Yes. The script is here:

• https://github.com/OSGeo/grass/blob/main/utils/grass_html2md.sh
• https://github.com/OSGeo/grass/blob/main/utils/pandoc_codeblock.lua

This was html to markdown, I am not sure how relevant is that to markdown to man conversion. My assumption was we don't want pandoc as dependency and it would likely require some tweaks.