message: Update login paragraph in crates-io docs.
diff: @@ -21,7 +21,8 @@ $ cargo login abcdefghijklmnopqrstuvwxyz012345
  ```
  This command will inform Cargo of your API token and store it locally in your
  -`~/.cargo/config`. Note that this token is a **secret** and should not be shared
  +`~/.cargo/credentials` (previously it was `~/.cargo/config`).
  +Note that this token is a **secret** and should not be shared
  with anyone else. If it leaks for any reason, you should regenerate it
  immediately.
  