Cats: Remove fine-grained imports from docs

[tpolecat]

Some of the doc pages use fine-grained imports, which we should discourage as it's very tricky (so tricky in fact that most advanced users don't even try) and is a source of discouraging problems and many questions on the Gitter channel. Can we go through the doc and remove them?

[calvinbrown085]

Hi @tpolecat do you have an example here? I'm guessing it's somewhere we can import ._ instead?

[LukaJCB]

@calvinbrown085
In general when there's docs where anything apart from import cats.implicits._ is used, change it to cats.implicits._ instead. So e.g. in https://github.com/typelevel/cats/blob/master/docs/src/main/tut/typeclasses/applicative.md

you'll see this:

import cats.instances.list._
import cats.syntax.traverse._

That should be changed to just

import cats.implicits._

[calvinbrown085]

@LukaJCB Ah, that makes sense! I can try to go through and find some of these to fix

[calvinbrown085]

Is there anything else we need here? Or can we close this issue?

[ceedubs]

I think that this can be closed out now. Thanks, @calvinbrown085!