[release-branch.go1.13] strconv: update documentation
Fixes #33750.
Updates #31197.
Change-Id: I26f63cef57e5f0eec85b84554c82f6d47b4f41a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/191078
Reviewed-by: Robert Griesemer <gri@golang.org>
(cherry picked from commit
d9b13233378668a4fd24ac5d044e9d550cd2a8be)
Reviewed-on: https://go-review.googlesource.com/c/go/+/191168
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>