Update main-it.json
Update main-it.json

- added a few missing lines
- changed some fragmented phrases, so that they sound fluent, once reunited
- gave coherence to the usage of the persons (I, or you) in some mismatching title and dialog boxes
gpolitis/jitsi-meet,jitsi/jitsi-meet,gpolitis/jitsi-meet,jitsi/jitsi-meet,jitsi/jitsi-meet,gpolitis/jitsi-meet,gpolitis/jitsi-meet,jitsi/jitsi-meet,gpolitis/jitsi-meet,gpolitis/jitsi-meet,gpolitis/jitsi-meet,jitsi/jitsi-meet,gpolitis/jitsi-meet,jitsi/jitsi-meet,jitsi/jitsi-meet,jitsi/jitsi-meet