Update arguments for custom planner and controller (#687)

Signed-off-by: Maurice-1235 <mauricepurnawan@gmail.com>

Author: mini-1235

plugin_tutorials/docs/writing_new_nav2controller_plugin.rst

@@ -70,8 +70,8 @@ The list of methods, their descriptions, and necessity are presented in the tabl
 | computeVelocityCommands() | Method is called when a new velocity command is demanded by the controller server     | Yes                    |
 |                           | in-order for the robot to follow the global path. This method returns a               |                        |
 |                           | `geometry_msgs\:\:msg\:\:TwistStamped` which represents the velocity command for the  |                        |
-|                           | robot to drive.  This method passes 2 parameters: reference to the current robot      |                        |
-|                           | pose and its current velocity.                                                        |                        |
+|                           | robot to drive.  This method passes 3 parameters: reference to the current robot      |                        |
+|                           | pose, its current velocity, and a pointer to the `nav2_core::GoalChecker`.            |                        |
 +---------------------------+---------------------------------------------------------------------------------------+------------------------+
 | cancel()                  | Method is called when the controller server receives a cancel request. If this method | No                     |
 |                           | is unimplemented, the controller will immediately stop when receiving a cancel        |                        |

plugin_tutorials/docs/writing_new_nav2planner_plugin.rst

@@ -60,7 +60,8 @@ Let's learn more about the methods needed to write a planner plugin.
 +----------------------+-----------------------------------------------------------------------------+-------------------------+
 | createPlan()         | Method is called when planner server demands a global plan for specified    | Yes                     |
 |                      | start and goal pose. This method returns `nav_msgs\:\:msg\:\:Path` carrying |                         |
-|                      | global plan. This method takes 2 input params: start pose and goal pose.    |                         |
+|                      | global plan. This method takes 3 input params: start pose, goal pose and    |                         |
+|                      | a function to check if the action has been canceled.                        |                         |
 +----------------------+-----------------------------------------------------------------------------+-------------------------+
 
 For this tutorial, we will be using methods ``StraightLine::configure()`` and ``StraightLine::createPlan()`` to create straight-line planner.