add an example how to use tunable event
add an example how to use tunable event

Signed-off-by: Pavel Hrdina <d4772d05997b8abf035041e3b4f4996380ea7e7a@redhat.com>

elmarco/libvirt,nertpinx/libvirt,andreabolognani/libvirt,olafhering/libvirt,crobinso/libvirt,taget/libvirt,VenkatDatta/libvirt,eskultety/libvirt,VenkatDatta/libvirt,datto/libvirt,elmarco/libvirt,jfehlig/libvirt,andreabolognani/libvirt,olafhering/libvirt,jardasgit/libvirt,rlaager/libvirt,agx/libvirt,fabianfreyer/libvirt,agx/libvirt,libvirt/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,shugaoye/libvirt,rlaager/libvirt,zippy2/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,datto/libvirt,andreabolognani/libvirt,jfehlig/libvirt,shugaoye/libvirt,crobinso/libvirt,rlaager/libvirt,crobinso/libvirt,taget/libvirt,nertpinx/libvirt,andreabolognani/libvirt,elmarco/libvirt,jardasgit/libvirt,nertpinx/libvirt,datto/libvirt,shugaoye/libvirt,crobinso/libvirt,datto/libvirt,taget/libvirt,olafhering/libvirt,agx/libvirt,agx/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,agx/libvirt,fabianfreyer/libvirt,zippy2/libvirt,zippy2/libvirt,eskultety/libvirt,shugaoye/libvirt,elmarco/libvirt,libvirt/libvirt,shugaoye/libvirt,taget/libvirt,datto/libvirt,jardasgit/libvirt,nertpinx/libvirt,libvirt/libvirt,taget/libvirt,zippy2/libvirt,VenkatDatta/libvirt,eskultety/libvirt,jfehlig/libvirt,eskultety/libvirt,olafhering/libvirt,elmarco/libvirt,jfehlig/libvirt,nertpinx/libvirt,rlaager/libvirt,andreabolognani/libvirt,rlaager/libvirt,libvirt/libvirt,eskultety/libvirt