Very old markdown processing libraries

[jb-dev1]

The following markdown-related dependencies in the ai-chatbot app are quite outdated:

After reading about a few XSS attacks and other posts I've seen about getting LLMs to generate unsafe content (especially with streaming/progressive UI rendering), this seems appropriate for a demo/template app.

[gianpaj]

can be closed. all are up to date, except for the math plugin that was removed