Update H/h command to implemented...though not in many rigs

doc/man1/rigctl.1

@@ -939,7 +939,7 @@ Set memory
 .RI \(aq Channel \(aq
 data.
 .IP
-Not implemented yet.
+Sets memory channel information
 .
 .TP
 .BR h ", " get_channel
@@ -947,7 +947,7 @@ Get memory
 .RI \(aq Channel \(aq
 data.
 .IP
-Not implemented yet.
+Returns programmed channel information for specified channel
 .
 .TP
 .BR A ", " set_trn " \(aq" \fITransceive\fP \(aq