To do mapping run slam.launch file along with telop. Also, you can which slam_method to use among [Gmapping, Karto, Hector, Cartographer].
Terminal 1: roslaunch test_slam slam.launch slam_method:=gmapping #here gmapping is default
Terminal 2: roslaunch test_slam teleop.launch
After mapping you can run navigation by running navigation.launch file.
Terminal: roslaunch test_slam navigation.launch
Contains various launch files related to slam, navigation, gazebo, slam_methods.
Contain .world file, one which is used gazebo.
This is where map files are saved.
Contains mesh files which are used in robot
Contains param files like base_local_planner_params.yaml
Contains other configuration file like karto_mapper_params.yaml
Contains saved rviz configuration.
Contains robot model urdfs. Here burger.