Clarify argument groups

sbotc.1

@@ -9,13 +9,22 @@
 .Nm
 .Op Fl j
 .Op Fl T
+.
+.Oo
 .Op Fl n
+|
 .Op Fl c Ar cap
+.Op Fl k Ar key
+.Op Fl K Ar keypair_seed
+.Oc
+.
+.Oo
 .Op Fl s Ar host
 .Op Fl p Ar port
+|
 .Op Fl u Ar socket_path
-.Op Fl k Ar key
-.Op Fl K Ar keypair_seed
+.Oc
+.
 .Op Fl t Ar type
 .Ar method
 .Op Ar argument ...

sbotc.c

@@ -97,7 +97,9 @@ static const unsigned char ssb_cap[] = {
 };
 
 static void usage() {
-	fputs("usage: sbotc [-j] [-T] [-n] [-c <cap>] [-s <host>] [-p <port>] [-u <socket_path>] [-k <key>] [-K <keypair_seed>]\n"
+	fputs("usage: sbotc [-j] [-T]\n"
+	      "             [ [-n] | [-c <cap>] [-k <key>] [-K <keypair_seed>] ]\n"
+	      "             [ [-s <host>] [-p <port>] | [-u <socket_path>] ]\n"
 	      "             [-t <type>] <method> [<argument>...]\n", stderr);
 	exit(EXIT_FAILURE);
 }