Fixed Docs for Behavior tree (#772)

* Fixed Docs for Behavior tree

Signed-off-by: Jad El Hajj <jad.elhajj@inmind.ai>

* Added section to the migartion guide for the new BT feature

Signed-off-by: Jad El Hajj <jad.elhajj@inmind.ai>

* Update migration/Iron.rst

Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>

* Update migration/Iron.rst

Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>

* Update migration/Iron.rst

Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>

* Update migration/Iron.rst

Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>

* Moved to Kilted

Signed-off-by: Jad El Hajj <jad.elhajj@inmind.ai>

---------

Signed-off-by: Jad El Hajj <jad.elhajj@inmind.ai>
Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>
Co-authored-by: Steve Macenski <stevenmacenski@gmail.com>

Author: Jad-ELHAJJ

configuration/packages/bt-plugins/actions/NavigateThroughPoses.rst

@@ -52,7 +52,7 @@ Input Ports
   ====== =======
 
   Description
-        Behavior tree absolute path. If none is specified, NavigateThroughPoses action server uses a default behavior tree.
+        Behavior tree absolute path or ID. If none is specified, NavigateThroughPoses action server uses a default behavior tree.
 
 Output Ports
 ------------

configuration/packages/bt-plugins/actions/NavigateToPose.rst

@@ -52,7 +52,7 @@ Input Ports
   ====== =======
 
   Description
-        Behavior tree absolute path. If none is specified, NavigateToPose action server uses a default behavior tree.
+        Behavior tree absolute path or ID. If none is specified, NavigateToPose action server uses a default behavior tree.
 
 Output Ports
 ------------
@@ -86,4 +86,4 @@ Example
 
   <NavigateToPose goal="{goal}" server_name="NavigateToPose" server_timeout="10"
                   error_code_id="{navigate_to_pose_error_code}" error_msg="{navigate_to_pose_error_msg}"
-                  behavior_tree="<some-path>/behavior_trees/navigate_through_poses_w_replanning_and_recovery.xml"/>
+                  behavior_tree="NavigateThroughPosesWReplanningAndRecovery"/>

configuration/packages/configuring-bt-navigator.rst

@@ -236,6 +236,16 @@ Parameters
   Description
     Whether to allow QoS profiles to be overwritten with parameterized values.
 
+:bt_search_directories:
+
+  ============== =================================================
+  Type           Default
+  -------------- -----------------------------
+  vector<string> $(find-pkg-share nav2_bt_navigator)/behavior_trees
+  ============== =================================================
+
+  Description
+    List of directories that hosts behavior trees XML files. It is needed to register all behavior trees as well as subtrees.
 
 NavigateToPose Parameters
 *************************
@@ -361,6 +371,8 @@ Example
         path_blackboard_id: path
         waypoint_statuses_blackboard_id: waypoint_statuses
         navigators: ['navigate_to_pose', 'navigate_through_poses']
+        bt_search_directories:
+          - $(find-pkg-share nav2_bt_navigator)/behavior_trees
         navigate_to_pose:
           plugin: "nav2_bt_navigator::NavigateToPoseNavigator" # In Iron and older versions, "/" was used instead of "::"
           enable_groot_monitoring: false

migration/Kilted.rst

@@ -358,6 +358,14 @@ Example:
 
 See also :ref:`configuring_bt_navigator`
 
+Add BehaviorTree SubTrees Support
+---------------------------------
+
+The BehaviorTree engine now supports SubTrees in different files within directory(s) set through ``bt_search_directories`` parameter. This allows you to modularize your behavior trees into smaller components that can be reused across different trees.
+The interface now supports passing the behavior tree file or ID as input to the `loadBehaviorTree` method of the BT action server.
+Each behavior tree is now strictly required to have its own unique ID, therefore the need to replace `MainTre` to a unique ID. For example, in `navigate_through_poses_w_replanning_and_recovery.xml
+` `MainTree` can be replaced with `NavigateThroughPosesWReplanningAndRecovery`.
+
 Option to have custom window size and poly order in Savitsky-Golay Smoother
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