Adds diagram support to VS Code's builtin markdown preview using Kroki.
Create diagrams in markdown using fenced code blocks:
```mermaid
graph TD;
A-->B;
A-->C;
B-->D;
C-->D;
```
Supported formats:
- actdiag
- blockdiag
- bpmn
- bytefield
- c4plantuml
- d2
- dbml
- diagramsnet
- ditaa
- erd
- excalidraw
- graphviz
- mermaid
- nomnoml
- nwdiag
- packetdiag
- pikchr
- plantuml
- rackdiag
- seqdiag
- structurizr
- svgbob
- umlet
- vega
- vegalite
- wavedrom