Well this is rather easy, and interested people should not hesitate to contribute.
I started working on this in the following Pull Request #1209. There are things to improve in the manual rendering before we can merge this (and the improvement may require more hacking, so beginners are welcome but this may or may not turn out to be easy), but continuing the work of porting code example in the manual to the new caml_example environment is rather simple.
There is information in manual/README.md on how to build the manual and how to use the caml_example environment. Any further question can help improve this documentation.