Fix documentation for 8.x

Documentation should really be one of the last things committed to the 8.x-3.x branch. There is still a great amount of work to do and it will likely add, remove or change documentation a multitude of times. That being said, I would encourage to continue to update the patches here so when we're ready to tackle it we can.

This will be a release blocker for a stable 8.x release.

I really don't like repeating myself, so I'll try to further explain in case #2 wasn't clear enough. It's about: maintainer workflow, focus and priorities.

I, the maintainer and individual who spends the most time, energy and effort than anyone else on this project, would much rather spend it focusing on getting the actual code in 8.x-3.x stable first; before attempting to "document" things that could very well be broken or constantly change (e.g. duplicating efforts).

Keeping track of what "documentation" has been updated or not will be a nightmare (for me). I would know, I just did it for the 7.x-3.x branch for the past 3 months. In my time dealing with this, I learned that treating documentation as a final step or phase is what works best (for me): the ability to give everything a good "once over" after all is said and done. This allows the focus of the project to be done in different stages and reduces the chance of things being overlooked.

I'm not saying that any patches uploaded here won't eventually go in or that they're not important, just that it's currently not my focus.

As I had imagined, these related issues have severely changed the inner workings of the project. It mostly uses annotation plugin discovery now. The above commit is really just removing inaccurate information, most of which belongs to 7.x, and adding @todos. New 8.x documentation material will need to be created, especially around these annotation plugins.

I'm not quite ready (for myself) to fully start working on documentation, but I'm setting back to CNW so we can get started again.