Update documentation with h command

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>

src/info.c

@@ -24,9 +24,9 @@ void info_help(void)
 "    b, Left     Return to previous order\n"
 "    n, Up       Advance to next module\n"
 "    p, Down     Return to previous module\n"
+"    h, ?        Display available commands\n"
 "    1 - 0       Mute/unmute channels\n"
 "      !         Unmute all channels\n"
-"      ?         Display available commands\n"
 "      Z         Display current sequence\n"
 "      z         Toggle subsong explorer mode\n"
 "      l         Toggle loop mode\n"

src/main.c

@@ -279,7 +279,7 @@ int main(int argc, char **argv)
 		    opt.format & XMP_FORMAT_MONO ? "mono" : "stereo",
 		    opt.dsp & XMP_DSP_LOWPASS ? "" : " (no filter)");
 
-		report("Press h for help\n\n");
+		report("Press 'h' for help\n\n");
 	}
 
 	if (opt.probeonly) {

src/xmp.1

@@ -212,7 +212,7 @@ Pause or unpause module replay\&.
 Mute/unmute channels 1 to 10\&.
 .IP "\fB!\fP" 
 Unmute all channels\&.
-.IP "\fB?\fP" 
+.IP "\fBh\fP, \fB?\fP" 
 Display available commands\&.
 .IP "\fBZ\fP" 
 Display current sequence\&.