docs: add mermaid docs (#6971)

* docs: add mermaid docs

* fix link

* add development.mdx

* add codebase

* add parseEdge

* add subgraph

* convertors

* tweaks

* structure the codebase

* add docs for new diagram type

* decouple docs for flowchart parser

* fix broken links

* use diagram instead of chart

* revert package.json

* tweaks

* point root folder of mermaid-to-excalidraw to installation

* remove installation from sidebar children

* fix link

* update flowchart parser diagram

* update parser overview diagram

* update more diagrams

* remove note about change in element stroke

* update diagram

* increase size limit for excalidraw production bundle

* tweaks

* add link

* move codebase after introduction

* dummy

---------

Co-authored-by: dwelle <luzar.david@gmail.com>

src/packages/excalidraw/.size-limit.json

@@ -1,7 +1,7 @@
 [
   {
     "path": "dist/excalidraw.production.min.js",
-    "limit": "291 kB"
+    "limit": "305 kB"
   },
   {
     "path": "dist/excalidraw-assets/locales",