Merge branch '287-the-dyngroup-plugin-should-be-dyngroups-int-the-documentation' into 'dev'

Resolve "the dyngroup plugin should be dyngroups in the documentation"

See merge request fusiondirectory/user-manual!505

(cherry picked from commit c0a37b79)

33b85c6d :mabulance: fix(dyngroups) the dyngroup plugin should be dyngroups in the documentation