[Feature] Save/export diagram as image

[wcheek]

It would be nice to be able to copy/save diagrams as .png without exporting the entire page.

Eg) I create a diagram using mermaid.js:

graph LR
A(JVM Runtime) --> B[Java Heap]
style A fill:#f9f,stroke:#333,stroke-width:4px
A(JVM Runtime) --> C[Class loading]
A(JVM Runtime) --> D[JIT Compilation]

linkStyle 0,1,2 stroke:#0ff,stroke-width:2px,color:red;

Loading

Now I want to save this diagram as an image.

Feature request: Add a context menu option when right clicking on a diagram to allow to copy as image/save as image.

edit:
I found a great site to do this here. It would still be nice to have this feature native in Typora, but maybe it's a low priority.

[abnerlee]

duplicated with #5187