man: update finit.conf(5) with info on enabled and available

This should clarify the messup on the behalf of the mainatiner in not
documenting this properly, including the deviations introduced in v4.4

See issue #359 for a background.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

man/finit.conf.5

@@ -2,7 +2,7 @@
 .\" First parameter, NAME, should be all caps
 .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 .\" other parameters are allowed: see man(7), man(1)
-.Dd Apr 24, 2023
+.Dd July 11, 2023
 .Dt FINIT.CONF 5 SMM
 .Os Linux
 .Sh NAME
@@ -12,40 +12,64 @@
 .Nm /etc/finit.conf
 .Nm /etc/finit.d/*.conf
 .Nm /etc/finit.d/available/*.conf
+.Nm /etc/finit.d/enabled/*.conf
 .Sh DESCRIPTION
-.Nm finit
-can be configured using only the original
-.Pa /etc/finit.conf
-file or in combination with
-.Pa /etc/finit.d/*.conf .
-Useful for package-based Linux distributions \(em each package can
-provide its own "script" file.
+.Nm Finit
+based systems can be set up with a single file:
+.Pa /etc/finit.conf .
+This is the traditional way of doing it which can be ideal for some
+setups since it gives a great overview of the system configuration.
 .Pp
-.Bl -tag -width /etc/finit.d/*.conf -offset indent -compact
-.It Pa /etc/finit.conf
-Main configuration file
-.It Pa /etc/finit.d/*.conf
-Snippets, usually one service per file
-.El
+More comprehensive setups, however, require more careful planning.
+The recommendation is per-package
+.Cm *.conf
+files in
+.Pa /etc/finit.d/available/ .
+This allows end users to enable and disable parts of the system
+configuration at runtime.  Finit tracks which tasks and services belong
+to a given file, so that when the user calls
+.Cm initctl reload
+to activate the changes they have made, only the affected tasks and
+services are stopped, started, or restarted.  Hence, this approach is
+useful for modern package-based Linux distributions.
 .Pp
-Not all configuration directives are available in
-.Pa /etc/finit.d/*.conf
-and some directives are only available at bootstrap, runlevel
-.Cm S ,
-see the section
-.Sx Limitations
-below for details.
+The following sections describe the more of this in detail, starting
+with files, the file format, and available directives.  Remember to
+also visit the other manual pages (references at the bottom).
 .Sh FILES
 .Bl -tag -width /etc/finit.d/available/*.conf -compact
 .It Pa /etc/finit.conf
-Main configuration file
+Main configuration file, optional
 .It Pa /etc/finit.d/*.conf
-Static service definitions
+Static (system) service definitions
 .It Pa /etc/finit.d/available/*.conf
-Available services
+Available (installed) services
 .It Pa /etc/finit.d/enabled/*.conf
-Enabled services, symlinks from available
+Enabled services (symlink back)
 .El
+.Pp
+Static services,
+.Cm .conf
+files in
+.Pa /etc/finit.d/ ,
+cannot be enabled or disabled using
+.Cm initctl [enable | disable] service[.conf] .
+An enabled service is a symlink back to the corresponding
+.Cm ../available/
+service
+.Cm .conf
+file.  Please use the
+.Cm initctl
+tool to manage these symlinks to ensure proper operation.
+.Pp
+.Sy NOTE:
+Previous versions of
+.Nm Finit
+created symlinks in
+.Pa /etc/finit.d/
+if
+.Pa /etc/finit.d/enabled/
+was missing, this is as of v4.4 not supported.
 .Sh FILE FORMAT
 The file format is line based, empty lines and comments, lines starting
 with `#', are ignored.  A configuration directive starts with a keyword
@@ -960,6 +984,6 @@ settings in
 .Xr finit 8 ,
 .Xr initctl 8
 .Sh AUTHORS
-.Nm finit
+.Nm Finit
 was conceived and reverse engineered by Claudio Matsuoka.  Since v1.0,
 maintained by Joachim Wiberg, with contributions by many others.