Markdown support in help section

Galaxy 23.2 will ship with markdown support in the tool help section. Would be nice if we could support that and encourage users to use it.

* [ ] support markdown
* [ ] try to convert rst to markdown, especially if the profile version is >= 23.2
* [ ] support the new fancy `` syntax
* [ ] find those terms may be automatically and offer a conversion to this new syntax? We could use the new API (`/help/terms/{term_id}`)


xref: https://github.com/galaxyproject/galaxy/pull/18722

Start with the tool help section and compare the referenced Galaxy pull request 18722 with the requested behavior. Scope the RST-to-Markdown conversion for profiles at version 23.2 or later, the new HelpText syntax, and whether the /help/terms/{term_id} API can support term conversion. Done means the checklist is addressed and the help content is rendered as intended.

Written by the indexing model from the issue text.