docs: small man pages fixes and updates

- Previous hard-coded settings can be now be changes with riverctl or
  via environment variables
- Update "See also"
- Mod → Mod1

 .gitignore                                       |  2 +-
 build.zig                                        |  2 +-
 doc/{river-layouts.1.scd => river-layouts.7.scd} |  3 +--
 doc/river.1.scd                                  | 17 +++++++++++++----
 doc/riverctl.1.scd                               | 16 +++++++---------
 5 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/.gitignore b/.gitignore
index 32e32de..f2dfac3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
 zig-cache
 protocol/*.h
 protocol/*.c
-doc/*.1
+doc/*.[1-9]
diff --git a/build.zig b/build.zig
index 58f98c8..20e1ae2 100644
--- a/build.zig
+++ b/build.zig
@@ -218,7 +218,7 @@ const ScdocStep = struct {
         "doc/river.1.scd",
         "doc/riverctl.1.scd",
         "doc/rivertile.1.scd",
-        "doc/river-layouts.1.scd",
+        "doc/river-layouts.7.scd",
     };
 
     builder: *std.build.Builder,
diff --git a/doc/river-layouts.1.scd b/doc/river-layouts.7.scd
similarity index 98%
rename from doc/river-layouts.1.scd
rename to doc/river-layouts.7.scd
index 92fc2db..5cc9862 100644
--- a/doc/river-layouts.1.scd
+++ b/doc/river-layouts.7.scd
@@ -70,5 +70,4 @@ in a grid.
 ```
 
 # SEE ALSO
-*river*(1), *riverctl*(1)
-
+*river*(1), *riverctl*(1), *rivertile*(1)
diff --git a/doc/river.1.scd b/doc/river.1.scd
index 932273f..e79e6cb 100644
--- a/doc/river.1.scd
+++ b/doc/river.1.scd
@@ -27,14 +27,23 @@ bspwm based on wlroots and written in Zig.
 
 # CONFIGURATION
 
-View border width, gap sizes, and programs which should float are
-configured in _Config.zig_. Make your changes and recompile.
+You can define the list of programs which should float in _Config.zig_.
+Make your changes and recompile.
 
 Experimental XWayland support can be enabled on compile-time with the
 _-Dxwayland=true_ flag.
 
-Keyboard layout and other XKB options can be set in _Keyboard.zig_.
+# ENVIRONMENT
+
+The following environment variables are used to configure the keyboard. See
+*xkeyboard-config*(7) for possible values.
+
+- XKB_DEFAULT_MODEL
+- XKB_DEFAULT_LAYOUT
+- XKB_DEFAULT_VARIANT
+- XKB_DEFAULT_OPTIONS
+- XKB_DEFAULT_RULES
 
 # SEE ALSO
 
-*riverctl*(1), *bspwm*(1), *dwm*(1)
+*riverctl*(1), *river-layouts*(7), *rivertile*(1)
diff --git a/doc/riverctl.1.scd b/doc/riverctl.1.scd
index 98fb583..0d52de4 100644
--- a/doc/riverctl.1.scd
+++ b/doc/riverctl.1.scd
@@ -5,10 +5,8 @@ riverctl - command-line interface for controlling river
 
 # SYNOPSIS
 
-*riverctl* *close*|*declare-mode*|*enter-mode*|*exit*|*focus-output*|
-*focus-view*|*layout*|*map*|*mod-master-count*|*mod-master-factor*|
-*send-to-output*|*set-focused-tags*|*set-view-tags*|*spawn*|*toggle-float*|
-*toggle-focused-tags*|*toggle-view-tags*|*zoom* [_command specific arguments_]
+*riverctl*
+*close*|*declare-mode*|*enter-mode*|*exit*|*focus-output*|*focus-view*|*layout*|*map*|*mod-master-count*|*mod-master-factor*|*send-to-output*|*set-focused-tags*|*set-option*|*set-view-tags*|*spawn*|*toggle-float*|*toggle-focused-tags*|*toggle-view-tags*|*zoom* [_command specific arguments_]
 
 # DESCRIPTION
 
@@ -34,8 +32,8 @@ used to control and configure river.
 *layout* *full*|_command_
 	Provide a command which river will use for generating the layout of
 	non-floating windows on the currently focused output. See
-	*river-layouts*(1) for details on the expected formatting of the output
-	of layout commands. Alternatively, "full"can be given instead of a
+	*river-layouts*(7) for details on the expected formatting of the output
+	of layout commands. Alternatively, “full” can be given instead of a
 	command to cause river to use its single internal layout, in which
 	windows span the entire width and height of the output.
 
@@ -94,14 +92,14 @@ that tag 1 through 9 are visible.
 	Switch to given mode if it exits.
 
 *map* _mode_ _modifiers_ _key_ _command_
-	_mode_ is either *normal* (the default mode) or a mode created with
+	_mode_ is either “normal” (the default mode) or a mode created with
 	*declare-mode*. _modifiers_ is a list of one or more of the following
 	modifiers separated with a plus sign:
 
 	- Shift
 	- Lock (Caps lock)
 	- Control (Ctrl)
-	- Mod (Alt)
+	- Mod1 (Alt)
 	- Mod2
 	- Mod3
 	- Mod4 (Super, Logo, Windows)
@@ -132,4 +130,4 @@ See _contrib/config.sh_ for some basic keybindings.
 
 # SEE ALSO
 
-*river*(1), *bspc*(1)
+*river*(1), *river-layouts*(7), *rivertile*(1)