A minimal set of markdown support was added to the message field with 5.1 release of the plugin.
The following markdown variants are supported*
# Header 1
Message
## Header 2
Message
### Header 3
Message
### Header 4
Message*Need to be at beginning of line
*This is italicized*
**This is bolded**
***This is italicized and bolded***Links will open in a new tab -> target="_blank". This behavior cannot be changed.
[Link Name](https://github.com/jbrule)