modules: readme files regenerated - pv ... [skip ci]

src/modules/pv/README

@@ -694,8 +694,11 @@ xavi_child_rm("WhatEver", "FoO");
    at the index idx becomes the first and the ones before it are at the
    end of the list.
 
-   The first parameter has to be the name of XAVP in the root list. The
-   second parameter is the index of the XAVP that becomes the first one.
+   The first parameter has to be the name of XAVP in the root list.
+
+   The second parameter is the index of the XAVP that becomes the first
+   one (if it is greater than the number of XAVPs, modulo operation is
+   done first; if it is negative, it counts from the end of the list).
 
    The parameters can be with variables.