Resolve "Ajouter un exemple de passe à rangées périodiques"

Closes #635 (closed)

docs/en/calculators/pab/pab.md

@@ -85,3 +85,9 @@ Two graphs are present:
 - A general graph allowing the selection of any parameter from the result table in abscissa and ordinate.
 
 If several results are available due to the variation of one or two hydraulic parameters of the pass, all calculated water lines are displayed in the long profile, and a drop-down list allows to select the result to be displayed in the generalist table and graph.
+
+## Example session
+
+An example illustrating the conception of a fish ladder can be directly loaded
+at the address:
+https://cassiopee.g-eau.fr/#/loadsession/app%2Fexamples%2Fpab-complete-chain.json