improve man-page

htop.1

@@ -14,6 +14,21 @@ horizontally to see all processes and their full command lines.
 Tasks related to processes (killing, renicing) can be done without
 entering their PIDs.
 .br 
+.SH "COMMAND-LINE OPTIONS"
+.LP 
+The following flags are supported:
+.LP 
+.TP
+\fB\-d DELAY\fR
+Delay between updates, in tenths of seconds
+.TP
+\fB\-u USERNAME\fR
+Show only processes of a given user
+.TP
+\fB\-\-sort\-key COLUMN\fR
+Sort by this column (use --sort-key help for a column list)
+.PP
+.br 
 .SH "INTERACTIVE COMMANDS"
 .LP 
 The following commands are supported: