@arasbm For a 100 posts you can simply use the google groups' rss feed. Here's a post on stackexchange that explains how.
Unfortunately I could not find a way to page the feed so if you have more than a 100 posts this probably wont work.
By default, NodeBB has nodebb-plugin-markdown, which allows users to use the common markdown format in their posts.
**this is bolded**
this is bolded
It's fully documented here: https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet