Documenting commands to be view or window specific.

[UltraInstinct05]

This had been raised in guillermooo/sublime-undocs#273.
@FichteFoll If you could give an example on how you would like to see this being documented, I can take a shot at completing it.

[FichteFoll]

This will need a more carefully laid-out plan as it is hugely impactful, but my general idea is to base documentation for commands on a scraped document from the sigantures and docstrings of the default packages and combine that with the manual documentation of shipped commands as we already do for PackageDev and then build the resulting HTML based on that. This prodecure would already have all the necessary meta information available. Areas of concern would be on how to update the document from changes to the default packages and I am currently imagining a multi-layered process where we can inject updated information in a position that allows automatic replacement of entire files, making the updating process rather painless.

Currently, we are in a very early phase of drafting and experimenting with how to move forward with the docs regarding design, build pipeline and markup language, so I would suggest against doing large-effort changes to the current state of affairs and instead contribute in the issues that we are going to create and discuss in over the next few week(s) (hopefully singular).