lib/gis: Quote YAML description in parser --md-description output

[petrasovaa]

Closes #5907
Closes #5841
Problem:

The --md-description frontmatter emitted the description: value as an unquoted YAML. When a tool's label or description contains ": " (colon followed by space), YAML reads it as a nested mapping key and the frontmatter fails to parse, breaking the MkDocs page. r.viewshed is one example ("Default format: NULL ...").

This quotes the description value and escapes any embedded \ and ", so descriptions with colons (or quotes) produce valid YAML. Fixes the rendering for every affected tool, not just r.viewshed.

Tested locally, coded with AI.

[echoix]

Let's try this, when merging, find the two other PRs and the issue to close at the same time. I think they re not linked yet. One PR was from Corey I think.

[echoix]

Finally, your PR is not really different than #6270, that still misses situations that will happen as described in #5841. Maybe the ai will come up with a better implementation when pointed at what cases to fix and the general direction like I had written

[petrasovaa]

Finally, your PR is not really different than #6270, that still misses situations that will happen as described in #5841. Maybe the ai will come up with a better implementation when pointed at what cases to fix and the general direction like I had written

I totally forgot about all these... I need to review all the linked PRs/issues.

[petrasovaa]

Added stripping the quotes and undo the backslash escaping when building the tool index and topic pages so they no longer show literal quotes around descriptions.
This solution seemed simpler than reading the | syntax in Python.

[echoix]

Let’s try that, and see if we miss some syntax somewhere