Fix website build after migration

[wjkg]

TODO: rebase once @stibel/fix/apps is merged

Fixes remaining build errors in @doc/* and apps/website packages:

• esbuild errors when creating bundle for @doc/mdx-gen-cli
• issue with output of tsc in @doc/pages similar to Dependency upgrade fixes #17
• @doc/mdx-gen-cli:
  • failing or producing empty mdx files due to changes in react-reconciler
  • type and linter issues, missing test scripts
• switch to TS for docusaurus config — fixes an issue with type checking not picking up some @ aliases that need @docusaurus/preset-classic to be imported in the project
• other docusaurus changes related to upgrade from v2 to v3
• missing data-flow.svg files — instead of replicating the extra build step from the original repository, the optimized version cleared of Inkscape metadata is committed in the target directories. (The copy script could be restored in the future if needed, but I omitted it for simplicity, seeing as there's only one image for now)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.65%. Comparing base (9e12a16) to head (b4752d2).
⚠️ Report is 3 commits behind head on chore/migrate-render-html-with-history.

Additional details and impacted files

@@                           Coverage Diff                           @@
##           chore/migrate-render-html-with-history      #21   +/-   ##
=======================================================================
  Coverage                                   98.65%   98.65%           
=======================================================================
  Files                                         140      140           
  Lines                                        2076     2076           
  Branches                                      635      637    +2     
=======================================================================
  Hits                                         2048     2048           
  Misses                                         27       27           
  Partials                                        1        1           

Flag	Coverage Δ
css-processor	100.00% <ø> (ø)
render-html	97.83% <ø> (ø)
transient-render-engine	98.95% <ø> (ø)

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