fixing structure

Author: ARK3r

doc/writing_new_controller.rst

@@ -34,8 +34,10 @@ The following is a step-by-step guide to create source files, basic tests, and c
    3. Define a unique namespace for your controller. This is usually a package name written in ``snake_case``.
 
    4. Define the class of the controller, extending ``ControllerInterface``, e.g.,
+
       .. code:: c++
-      class ControllerName : public controller_interface::ControllerInterface
+   
+         class ControllerName : public controller_interface::ControllerInterface
 
    5. Add a constructor without parameters and the following public methods overriding the ``ControllerInterface`` definition: ``init``, ``command_interface_configuration``, ``state_interface_configuration``, ``on_configure``, ``on_activate``, ``on_deactivate``, ``update``.
       For exact definitions check the ``controller_interface/controller_interface.hpp`` header or one of the controllers from `ros2_controllers <https://github.com/ros-controls/ros2_controllers>`_.
@@ -105,8 +107,9 @@ The following is a step-by-step guide to create source files, basic tests, and c
    4. Add ament dependencies needed by the library. You should add at least those listed under 1.
 
    5. Export for pluginlib description file using the following command:
-      .. code:: cmake
 
+      .. code:: cmake
+   
          pluginlib_export_plugin_description_file(controller_interface <controller_name>.xml)
 
    6. Add install directives for targets and include directory.