Doc fixups (#546)

* add missing docs for number_of_threads parameter

* add missing docs for start_parameter_services parameter

* add missing docs for parameters, rename short variable name

* doc fixups

rclcpp/include/rclcpp/executors/multi_threaded_executor.hpp

@@ -45,6 +45,8 @@ public:
    * once.
    *
    * \param args common arguments for all executors
+   * \param number_of_threads number of threads to have in the thread pool,
+   *   the default 0 will use the number of cpu cores found instead
    * \param yield_before_execute if true std::this_thread::yield() is called
    */
   RCLCPP_PUBLIC

rclcpp/include/rclcpp/node.hpp

@@ -91,6 +91,8 @@ public:
    * \param[in] use_global_arguments False to prevent node using arguments passed to the process.
    * \param[in] use_intra_process_comms True to use the optimized intra-process communication
    * pipeline to pass messages between nodes in the same process using shared memory.
+   * \param[in] start_parameter_services True to setup ROS interfaces for accessing parameters
+   * in the node.
    */
   RCLCPP_PUBLIC
   Node(

rclcpp/include/rclcpp/subscription.hpp

@@ -59,6 +59,7 @@ public:
    * \param[in] type_support_handle rosidl type support struct, for the Message type of the topic.
    * \param[in] topic_name Name of the topic to subscribe to.
    * \param[in] subscription_options options for the subscription.
+   * \param[in] is_serialized is true if the message will be delivered still serialized
    */
   RCLCPP_PUBLIC
   SubscriptionBase(
@@ -161,6 +162,7 @@ public:
    * The constructor for a subscription is almost never called directly. Instead, subscriptions
    * should be instantiated through Node::create_subscription.
    * \param[in] node_handle rcl representation of the node that owns this subscription.
+   * \param[in] type_support_handle rosidl type support struct, for the Message type of the topic.
    * \param[in] topic_name Name of the topic to subscribe to.
    * \param[in] subscription_options options for the subscription.
    * \param[in] callback User defined callback to call when a message is received.
@@ -168,7 +170,7 @@ public:
    */
   Subscription(
     std::shared_ptr<rcl_node_t> node_handle,
-    const rosidl_message_type_support_t & ts,
+    const rosidl_message_type_support_t & type_support_handle,
     const std::string & topic_name,
     const rcl_subscription_options_t & subscription_options,
     AnySubscriptionCallback<CallbackMessageT, Alloc> callback,
@@ -177,7 +179,7 @@ public:
     Alloc>::create_default())
   : SubscriptionBase(
       node_handle,
-      ts,
+      type_support_handle,
       topic_name,
       subscription_options,
       rclcpp::subscription_traits::is_serialized_subscription_argument<CallbackMessageT>::value),