[pycall plugin] no example with vertical bar to give a python script in the documentation

[jmorice91]

In the ex10 of the tutorial, we use "exec: |" to define the python script in the next line. There is no example in the documentation using a vertical bar after "exec"

[jbigot]

This is a yaml feature, not a PDI feature per se, but it would indeed be interesting to have an example