docs: document what to do on AVAHI_ERR_DISCONNECTED (see #278)
docs: document what to do on AVAHI_ERR_DISCONNECTED (see #278)

heftig/avahi-1,heftig/avahi,Distrotech/avahi,gloryleague/avahi,gloryleague/avahi,Kisensum/xmDNS-avahi,heftig/avahi-1,catta-x/catta,heftig/avahi,Kisensum/xmDNS-avahi,gloryleague/avahi,Kisensum/xmDNS-avahi,everbase/catta,Kisensum/xmDNS-avahi,heftig/avahi-1,lathiat/avahi,lathiat/avahi,heftig/avahi-1,Kisensum/xmDNS-avahi,lathiat/avahi,catta-x/catta,Kisensum/xmDNS-avahi,Distrotech/avahi,heftig/avahi,heftig/avahi-1,heftig/avahi,heftig/avahi,everbase/catta,Distrotech/avahi,lathiat/avahi,heftig/avahi,lathiat/avahi,Distrotech/avahi,Distrotech/avahi,gloryleague/avahi,gloryleague/avahi,heftig/avahi-1,lathiat/avahi,catta-x/catta,gloryleague/avahi,everbase/catta,Distrotech/avahi