Update async api docs

Author: deliahu

docs/workloads/async/configuration.md

@@ -19,10 +19,10 @@
           mem: <string>  # memory request for the container; one unit of memory is one byte and can be expressed as an integer or by using one of these suffixes: K, M, G, T (or their power-of two counterparts: Ki, Mi, Gi, Ti) (default: Null)
           shm: <string>  # size of shared memory (/dev/shm) for sharing data between multiple processes, e.g. 64Mi or 1Gi (default: Null)
         readiness_probe:  # periodic probe of container readiness; traffic will not be sent into the pod unless all containers' readiness probes are succeeding (optional)
-          http_get:  # specifies an http endpoint which must respond with status code 200 (only one of http_get, tcp_socket, and exec may be specified)
+          http_get:  # specifies an http endpoint which must respond with status code 200 (only one of http_get and tcp_socket may be specified)
             port: <int|string>  # the port to access on the container (required)
             path: <string>  # the path to access on the HTTP server (default: /)
-          tcp_socket:  # specifies a port which must be ready to receive traffic (only one of http_get, tcp_socket, and exec may be specified)
+          tcp_socket:  # specifies a port which must be ready to receive traffic (only one of http_get and tcp_socket may be specified)
             port: <int|string>  # the port to access on the container (required)
           initial_delay_seconds: <int>  # number of seconds after the container has started before the probe is initiated (default: 0)
           timeout_seconds: <int>  # number of seconds until the probe times out (default: 1)