Add mappings to support conversion of contents other than Mapdl commands

### 📝 Description of the feature

After testing conversion of other XML-Docbook contents, the conversion is successful but empty. It means the content types to be converted are ignored because not mapped to any output type.
My guess is we have to map every xml tag (here in blue) to a rst style for the output to be correct:

If possible, a .MD output would be preferable.

### 💡 Steps for implementing the feature

_No response_

### 🔗 Useful links and references

_No response_

No implementation files, tests, or entry points are named. Start by locating the XML-to-output mapping used for non-MapDL XML-DocBook content, identify which content types are ignored, and clarify whether RST or Markdown is the required output. Done means supported content converts to non-empty output with coverage for the newly mapped types.

Written by the indexing model from the issue text.