Fix __String vs string type mismatch in imports transformer by
converting escapedText to string. Add @ts-expect-error for TypeDoc
Converter.on() which exists at runtime but is not in public type
exports.
Replace the legacy dgeni/gulp documentation pipeline with TypeDoc
and typedoc-plugin-markdown. Generates plugin README files with
extracted @Plugin() decorator metadata. Register custom JSDoc tags
used by plugin source files.
Daniel Sogl