[Feature Request] Mermaid Diagram Support
Is your feature request related to a problem? Please describe.
I use markdown to create my lecture notes and would like to preview my mermaid diagrams as I write them out.
Describe the solution you'd like
Similar to other markdown editors like Marker, I'd like to use the following format:
```mermaid
graph TD
simple --> diagram
```
and have a preview of the most recent valid diagram shown on the preview pane.
Describe alternatives you've considered
I have used other editors like typora and marker but neither have the polish or integration with GTK that this project has.