Updated build instructions

README.md

@@ -26,25 +26,14 @@ Here are a few videos of FrequencyCam in action:
 Currently tested on Ubuntu 20.04 under ROS2 Galactic.
 
 ## How to build
-Create a workspace (``~/ws``), clone this repo, and use ``vcs``
-to pull in the remaining dependencies:
-```
-pkg=frequency_cam
-mkdir -p ~/${pkg}_ws/src
-cd ~/${pkg}_ws
-git clone https://github.com/berndpfrommer/${pkg}.git src/${pkg}
-cd src
-vcs import < ${pkg}/${pkg}.repos
-cd ..
-```
-
-The build procedure is standard for ROS1 (catkin) and ROS2, so here is
-only the ROS2 syntax:
 
+Set the following shell variables:
+```bash
+repo=frequency_cam
+url=https://github.com/berndpfrommer/${repo}.git
 ```
-cd ~/ws
-colcon build --symlink-install --cmake-args -DCMAKE_BUILD_TYPE=RelWithDebInfo  # (optionally add -DCMAKE_EXPORT_COMPILE_COMMANDS=1)
-```
+and follow the [instructions here](https://github.com/ros-misc-utilities/.github/blob/master/docs/build_ros_repository.md)
+
 
 ## How to use