docs: Added material mkdocs tags plugin

[cwhite911]

This uses existing keywords in Material MkDocs tags plugin to show tag. The tags mirror the keywords in terms of list and index, but are simpler, completely driven by mkdocs without any needed for custom code. The tool family and topic logic is obviously not include. More evaluation and de-duplication with keywords is needed (as a next step).

Adds tags to parser output which are just keywords but in full YAML syntax (mkdocs consumes tags by default, but can be configured).

Uses absolute URL instead of relative links in footer to make links from addons work.

Addresses Issue #5091

This pull request includes multiple changes to improve the documentation and tagging system in the project.

Modified md keyword generation in documentation:

• lib/gis/parser_rest_md.c: Changed the keyword output to use "tags" instead, and adjusted the format to include brackets.
• lib/gis/parser_rest_md.c: Removed the conditional keyword section to streamline the output format.

Updates to build process and documentation files:

• man/Makefile: Added tags.md to the list of documentation source files and ensured it gets installed correctly. [1] [2]
• man/mkdocs/mkdocs.yml: Enabled the tags plugin in the MkDocs configuration to support tag-based navigation.
• man/mkdocs/overrides/partials/footer.html: Updated the footer to include a link to the new Tags index.
• man/mkdocs/tags.md: Added a new file to list relevant tags for the documentation.

[wenzeslaus]

While just using the tags instead of a currently working custom keywords system is not a priority, and some pieces will need to me preserved for keeping functioning URLs (if someone links https://grass.osgeo.org/grass-stable/manuals/keywords.html), this may help solving keywords for addons which currently work for HTML, but not for Markdown. However, given this needs the addon situation to be resolved, let's wait with this a bit to see how #5152 develops.

Example with a addon-only keyword is v.vect.stats.multi.md with keyword 'columns'.

[cwhite911]

While just using the tags instead of a currently working custom keywords system is not a priority, and some pieces will need to me preserved for keeping functioning URLs (if someone links https://grass.osgeo.org/grass-stable/manuals/keywords.html), this may help solving keywords for addons which currently work for HTML, but not for Markdown.

This is an easy fix. We just need to leave the keyword tag in the header for now.

Example with a addon-only keyword is v.vect.stats.multi.md with keyword 'columns'.

I'll need to see this because I'm not following.

However, given this needs the addon situation to be resolved, let's wait with this a bit to see how #5152 develops.

I agree this can wait until we resolve the addons.

[wenzeslaus]

I like it, but I meant to request changes for the footer.

[wenzeslaus]

Please, update from main. #5152, #5177, and #5175 are now on main, so the custom keyword system including addons is in a good shape and running the the CI. Then, we can see the result in the artifact from the Documentation workflow.

[petrasovaa]

The Tags index in the footer doesn't work, links to ./addons/tags.html, but that's the same for keywords.

[cwhite911]

The Tags index in the footer doesn't work, links to ./addons/tags.html, but that's the same for keywords.

This is fixed now. They needed to be set not to use relative paths that why it was picking up the sub-directory.

[wenzeslaus]

This looks good to me as far as functionality. Next step is to decide on the details and interaction between custom keywords representation and the tags.

The TOC on tags page does not work, but it does not work on the keywords one either. The solution in the HTML doc was TOC by first letter, but I don't know if a TOC is even needed here.

I think the footer needs some other solution (some which will work for local files and multiple versions), but it is not directly related, so let's address that separately.