doc issues

[freeznet]

• the example's intend in docs/connectors/run-connector is not correct.
  

• all examples and code blocks are using MaxPendingAsyncRequests, but the correct one should be maxPendingAsyncRequests. This issue is addressed in add CRD validation with WebHook function-mesh#238

• CRD docs missing ClusterName, for both function, sink, and source. https://github.com/streamnative/function-mesh/blob/master/api/v1alpha1/function_types.go#L36