Right.

A - You wire the dome light as you normally do, with a power wire to the switch - the switch connects and disconnects that.

B - Then you add another power wire from the relay to the "hot side" of the switch - the relays connects and disconnects that.

PS - I just updated my web page ... see what you think:
Update

~~ Alan Horvath
1954 Chevy Pickup
Singing his praises in the
Passing Lane