Rephrase D-Bus user docs
Rephrase D-Bus user docs

Clarify that dbus-proxy is a submodule in SoftwareContainer.

Signed-off-by: Therese Nordqvist <2d0f96d8a993fd0656366c2e00899126ff42525a@pelagicore.com>

kursatkobya/softwarecontainer,Pelagicore/softwarecontainer,tobsan/softwarecontainer,tobsan/softwarecontainer,thenor/softwarecontainer,thenor/softwarecontainer,tobsan/softwarecontainer,kursatkobya/softwarecontainer,thenor/softwarecontainer,frznlogic/softwarecontainer,thenor/softwarecontainer,frznlogic/softwarecontainer,frznlogic/softwarecontainer,Pelagicore/softwarecontainer,kursatkobya/softwarecontainer,Pelagicore/softwarecontainer,tobsan/softwarecontainer,frznlogic/softwarecontainer,Pelagicore/softwarecontainer,kursatkobya/softwarecontainer