Reword and clarify parts of the manual

Mostly related to the utilities options.

catgirl.1

@@ -95,8 +95,13 @@ following their corresponding flags.
 .It Fl C Ar util | Cm copy No = Ar util
 Set the utility used by
 .Ic /copy .
-Use more than once to add arguments to
+Subsequent
+.Cm copy
+options append arguments to
 .Ar util .
+The URL to copy is provided to
+.Ar util
+on standard input.
 The default is the first available of
 .Xr pbcopy 1 ,
 .Xr wl-copy 1 ,
@@ -158,19 +163,27 @@ with a hash of its original value.
 .
 .It Fl N Ar util | Cm notify No = Ar util
 Send notifications using a utility.
-Use more than once to add arguments to
+Subsequent
+.Cm notify
+options append arguments to
 .Ar util .
-Two additional arguments are passed to
-.Ar util :
-a title and a description,
+The window name and message
+are provided to
+.Ar util
+as two additional arguments,
 appropriate for
 .Xr notify-send 1 .
 .
 .It Fl O Ar util | Cm open No = Ar util
 Set the utility used by
 .Ic /open .
-Use more than once to add arguments to
+Subsequent
+.Cm open
+options append arguments to
 .Ar util .
+The URL to open is provided to
+.Ar util
+as an argument.
 The default is the first available of
 .Xr open 1 ,
 .Xr xdg-open 1 .
@@ -209,8 +222,9 @@ with
 using SASL PLAIN.
 Since this requires the account password
 in plain text,
-it is recommended to use SASL EXTERNAL instead with
-.Fl e .
+it is recommended to use CertFP instead.
+See
+.Sx Configuring CertFP .
 .
 .It Fl c Ar path | Cm cert No = Ar path
 Load the TLS client certificate from
@@ -233,7 +247,7 @@ Authenticate using SASL EXTERNAL,
 also known as CertFP.
 The TLS client certificate is loaded with
 .Fl c .
-For more information, see
+See
 .Sx Configuring CertFP .
 .
 .It Fl g Ar path
@@ -380,7 +394,8 @@ to your account:
 .It
 Enable SASL EXTERNAL
 to require successful authentication
-when connecting:
+when connecting
+(not possible on all networks):
 .Bd -literal -offset indent
 cert = example.pem
 sasl-external
@@ -512,7 +527,7 @@ or temporarily add a pattern.
 To permanently add a pattern, use
 .Fl i .
 .It Ic /move Oo Ar name Oc Ar num
-Move named window to number.
+Move the named or current window to number.
 .It Ic /open Op Ar count
 Open each of
 .Ar count
@@ -786,7 +801,7 @@ if requested by the user,
 .Dv EX_UNAVAILABLE
 (69)
 if the connection is lost,
-and >0 if an error occurs.
+and >0 if any other error occurs.
 .
 .Sh EXAMPLES
 Join
@@ -978,10 +993,10 @@ catgirl tilde
 .Ss Extensions
 The
 .Nm
-client can take advantage of the
+client implements the
 .Sy causal.agency/consumer
 vendor-specific IRCv3 capability
-implemented by
+offered by
 .Xr pounce 1 .
 The consumer position is stored in the
 .Cm save