Have followed instructions to disable cache for development but it's still caching
You've disabled the render, dynamic_page_cache, and page cache bins; plugin discovery is stored in a different bin (discovery). You probably don't want to disable that bin, as it's likely to slow the site down appreciably (the project will be scanned for plugins on every request).

If you just keep in mind that you need to rebuild caches manually when you add a plugin, implement a hook, or add/change a .yml file in the module's root, you'll be able to work a lot faster.