Mermaid flowchart feature

[kai]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
I would like to be able to export trees into mermaid flowcharts such as

flowchart TD
    A[Christmas] -->|Get money| B(Go shopping)
    B --> C{Let me think}
    C -->|One| D[Laptop]
    C -->|Two| E[iPhone]
    C -->|Three| F[fa:fa-car Car]

Documentation: http://mermaid.js.org/syntax/flowchart.html

Describe alternatives you've considered
There is no alternative other than manually creating the mermaid flowcharts.

Additional context
NA

[Kay Jan W.]

Hi, thanks for raising this issue! The fix is implemented in v0.13.0, do upgrade bigtree with the command pip install --upgrade bigtree.