[add] example shell for turtlebot4 with gz-ros and nav2

examples/ros2-turtlebot4-gz.nix

@@ -0,0 +1,26 @@
+# Environment containing basic ROS2 tools
+
+{ pkgs ? import ../. {} }:
+with pkgs;
+with rosPackages.jazzy;
+
+mkShell {
+  nativeBuildInputs = [
+    (buildEnv {
+      paths = [
+        ros-core
+        colcon
+        geometry-msgs
+        turtlebot4-desktop
+        turtlebot4-simulator
+        slam-toolbox
+        nav2-minimal-tb4-sim
+        nav2-minimal-tb3-sim
+        # rqt metapackages
+        rqt-common-plugins
+        rqt-tf-tree
+        tf2-tools
+      ];
+    })
+  ];
+}

flake.nix

@@ -21,6 +21,7 @@
         example-turtlebot3-gazebo = import ./examples/turtlebot3-gazebo.nix { inherit pkgs; };
         example-ros2-basic = import ./examples/ros2-basic.nix { inherit pkgs; };
         example-ros2-gz = import ./examples/ros2-gz.nix { inherit pkgs; };
+        example-ros2-turtlebot4-gz = import ./examples/ros2-turtlebot4-gz.nix { inherit pkgs; };
 
         # Development environment for the custom GitHub action
         nix-ros-build-action = pkgs.callPackage ./.github/actions/nix-ros-build-action/shell.nix { };