Docs say CallProperties.options, but implementation is CallProperties.callOptions.

### Problem description
While creating a solution to dynamically set the `deadline` on every call, I took this route:
[`callInvocationTransformer`](https://grpc.github.io/grpc/node/grpc.Client.html#~callInvocationTransformer) =>
[`callProperties`](https://grpc.github.io/grpc/node/grpc.Client.html#~CallProperties) =>
[`callOptions`](https://grpc.github.io/grpc/node/grpc.Client.html#~CallOptions)

However, the docs say that the `CallOptions` value will be under the `options` key in the `callProperties` argument for the `callInvocationTransformer` function, but in the implementation it's under the `callOptions` key.

These 2 things are incongruent. May be easier to just fix the docs? I'd submit a PR, but it was not obvious to me where the documentation for this lived.