Service profile documentation has a few errors

## Bug Report

### What is the issue?

The documentation located here: https://linkerd.io/2/reference/service-profiles/ has 2 errors (that I know of):

1. In the _Route_ section:`responses` should be `responseClasses`
2. In the _Response class_ section: `isSuccess` should be `isFailure`

Start with the service profile documentation at https://linkerd.io/2/reference/service-profiles/ and review the Route and Response class sections. Done means correcting `responses` to `responseClasses` and `isSuccess` to `isFailure`, then checking the rendered page for the two fixes.

Written by the indexing model from the issue text.