Improve documentation on the type of options

To be more close to the implementation, use 'scope' for what was
previously called 'type', and improve the documentation on the actual
option types (i.e. flag, choices, ...).

Rephrase the sentence before {set,show}-options commands to be similar
to the one in the HOOKS section, since show-options does not actually
set options.

Co-authored-by: Julian Prein <julian@druck.dev>

tmux.1

@@ -3850,13 +3850,45 @@ option prevents errors being returned.
 .Sh OPTIONS
 The appearance and behaviour of
 .Nm
-may be modified by changing the value of various options.
+may be modified by changing the value of various options. Each option belongs to
-There are four types of option:
+one or multiple scopes
-.Em server options ,
+.Po
-.Em session options ,
+.Em server ,
-.Em window options ,
+.Em session ,
+.Em window ,
 and
-.Em pane options .
+.Em pane
+.Pc and has a type
+.Po
+.Em string ,
+.Em number ,
+.Em key ,
+.Em colour ,
+.Em flag ,
+.Em choice ,
+or
+.Em command
+.Pc . Values of
+.Em flag Ns -type
+options may be one of:
+.Ic 1 ,
+.Ic on ,
+.Ic yes ,
+.Ic 0 ,
+.Ic off ,
+or
+.Ic no ;
+for possible
+.Em choice
+values, see the respective option; for
+.Em key
+options, the
+.Sx KEY BINDINGS
+section; and for
+.Em colour
+options, the
+.Sx STYLES
+section.
 .Pp
 The
 .Nm
@@ -3920,7 +3952,7 @@ $ tmux show -wv @foo
 abc123
 .Ed
 .Pp
-Commands which set options are as follows:
+Options are managed with these commands:
 .Bl -tag -width Ds
 .Tg set
 .It Xo Ic set-option
@@ -3943,7 +3975,7 @@ or
 .Fl s
 may be unnecessary -
 .Nm
-will infer the type from the option name, assuming
+will infer the scope from the option name, assuming
 .Fl w
 for pane options.
 If
@@ -3964,8 +3996,9 @@ unsets an option (like
 but if the option is a pane option also unsets the option on any panes in the
 window.
 .Ar value
-depends on the option and may be a number, a string, or a flag (on, off, or
+depends on the option and its type and can be omitted for flag and choice
-omitted to toggle).
+options to toggle it's value (choice options toggle between the first two
+choices).
 .Pp
 The
 .Fl o
@@ -4020,7 +4053,7 @@ or
 .Fl s
 may be unnecessary -
 .Nm
-will infer the type from the option name, assuming
+will infer the scope from the option name, assuming
 .Fl w
 for pane options.
 Global session or window options are listed if