ruby
PoC for the event-based plugin system with YARD parsing plugin
This PR introduces the event-based plugin system along with a YARD-parsing plugin as an example of concrete plugins.
It demonstrates how we can build practical plugins while keeping the core code small. In this case, YARD-related logic is encapsulated in a plugin and used only when users specify with --plugins option.
This YARD plugin successfully parses https://github.com/okuramasafumi/alba comments written with YARD, but doesn't print YARD-specific information such as types since current RDoc doesn't support type information.
This PR is completely proof of concept, and is not meant to be merged now. I'd like to discuss if this is the right way to extend RDoc for developers, and even for core team, and improve maintainability.
The original discussion is https://github.com/ruby/rdoc/discussions/1257
