net/http: correct Client.Do doc about context cancelation
The documentation of the Client.Do method and Get function incorrectly
stated that, in case of context cancelation, the returned url.Error
Timeout method returns true.
Update the documentation to correctly match the implementation.
See also CL 200798 that, due to an oversight, corrected only the
documentation of the Client.Get method.
Remove a TODO note added in CL 125575 (net/http: document that Client
methods always return *url.Error), since it is no longer applicable
after CL 200798 (net/http: fix and lock-in Client.Do docs on request
cancelation).
Fixes #46402
Change-Id: Ied2ee971ba22b61777762dbb19f16e08686634ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/323089 Reviewed-by: Damien Neil <dneil@google.com>
Trust: Michael Knyszek <mknyszek@google.com>