Dockerfile enhancement + build.sh added

[Tim-HW]

Hello there !

Thanks for your repo, I used it for one of my project. Here are the improvements I've made:

• I've added the build of livox-ros-driver2 inside the dockerfile
• "colcon build" process is added in the ros_entrypoint

So now, when you can modify the fast-lio folder then ./run.sh, and directly try it :D
Cheers

Tim