Update rotctl.1 to add some description of azimuth and elevation

doc/man1/rotctl.1

@@ -351,6 +351,10 @@ and
 .RI \(aq Elevation \(aq
 are floating point values.
 .IP
+Azimuth can be -180 to 540 depending on the rotator to allow for rotators facing south and the capabilities of the rotator.
+.IP
+Elevation can be -20 to 210 depending on the rotator.
+.IP
 For example:
 .
 .sp