update remaining references to "pyright" in the docs to "basedpyright"

[DetachHead]

previously i only updated the name in places where there's basedpyright-specific information, but it just causes confusion. see #581 (comment)

[DetachHead]

this is mostly addressed in #715. i didn't update all instances, some untouched areas of the docs where pyright is no different to basedmypy i left as-is since i think it makes it more clear what's basedpyright-specific