add river-control-unstable-v1 support

doc/riverguile.1

@@ -23,22 +23,60 @@ If certain handlers are installed it will run continously.
 .P
 Uppon launch, riverguile tries to load the script from the following paths
 in the given order:
-.IP  \(bu 2
+.IP \(bu 2
 \fBlayout.scm\fR
-.IP  \(bu 2
+.IP \(bu 2
 \fB$XDG_CONFIG_HOME/river/layout.scm\fR
-.IP  \(bu 2
+.IP \(bu 2
 \fB$HOME/.config/river/layout.scm\fR
-.IP  \(bu 2
+.IP \(bu 2
 \fB/etc/riverguile/layout.scm\fR
+.
+.
+.SH COMMANDS
 .P
+Riverguile exposes the special procedure
+\fB(riverctl \fR\fIfirst\fR . \fIrest\fR\fB)\fR, which can be used to send
+commands to the server in a similar fashion to
+.BR riverctl (1).
+All arguments must be strings.
+.P
+Here is an example of using this procedure to instruct river to spawn an
+instance of the
+.BR foot (1)
+terminal emulator:
+.P
+.RS
+.EX
+(\fBriverctl\fR "spawn" "foot")
+.EE
+.RE
+.P
+To make using this procedure more ergonomic you likely want to wrap it in a
+macro like this:
+.P
+.RS
+.EX
+(\fBdefine-syntax\fR R
+  (\fBsyntax-rules\fR ()
+    ((R first) (riverctl (\fBsymbol->string\fR 'first)))
+    ((R first . rest) (\fBapply\fR riverctl
+                             (\fBmap\fR \fBsymbol->string\fR
+                                  (\fBappend\fR '(first) 'rest))))))
+
+(R spawn foot)
+(R spawn \fB#{\fRnotify-send notification!\fB}#\fR)
+.EE
+.RE
+.P
+This macro can of course be further modified to suit your specific needs.
 .
 .
 .SH EVENT HANDLERS
 .P
-In the context of the script, a special procedure
-\fB(install-handler \fR\fIkey\fR \fIproc\fR\fB)\fR is available, which can be
-used to install event handlers.
+Riverguile exposes the special procedure
+\fB(install-handler \fR\fIkey\fR \fIproc\fR\fB)\fR, which can be used to install
+event handlers.
 The parameter \fIkey\fR is a symbol indicating for which event to install
 the procedure \fIproc\fR.
 The following keys are currently evailable: