add preamble text to each service-providing-module

modules/dnsmasq/default.nix

@@ -1,3 +1,10 @@
+## Dnsmasq
+## =======
+##
+## This module includes a service to provide DNS, DHCP, and IPv6
+## router advertisement for the local network.
+
+
 { lib, pkgs, config, ...}:
 let
   inherit (lib) mkOption types;

modules/firewall/default.nix

@@ -1,3 +1,9 @@
+## Firewall
+## ========
+##
+## Provides a service to create an nftables ruleset based on
+## configuration supplied to it.
+
 { lib, pkgs, config, ...}:
 let
   inherit (lib) mkOption types;

modules/hostapd/default.nix

@@ -1,3 +1,16 @@
+## Hostapd
+## =======
+##
+## Hostapd (host access point daemon) enables a wireless network
+## interface to act as an access point and authentication server,
+## providing IEEE 802.11 access point management, and IEEE
+## 802.1X/WPA/WPA2/EAP Authenticators. In less technical terms,
+## this service is what you need for your Liminix device to
+## provide a wireless network that clients can connect to.
+##
+## If you have more than one wireless network interface (e.g.
+## wlan0, wlan1) you can run an instance of hostapd on each of them.
+
 { lib, pkgs, config, ...}:
 let
   inherit (lib) mkOption types;

modules/ntp/default.nix

@@ -1,3 +1,11 @@
+## NTP
+## ===
+##
+## A network time protocol implementation so that your Liminix device
+## may synchronize its clock with an accurate time source, and
+## optionally also provide time service to its peers. The
+## implementation used in Liminix is Chrony
+
 { lib, pkgs, config, ...}:
 let
   inherit (lib) mkOption types;

modules/ppp/default.nix

@@ -1,3 +1,12 @@
+## PPP
+## ===
+##
+## A rudimentary PPPoE (PPP over Ethernet) configuration to address
+## the case where your Liminix device is connected to an upstream
+## network using PPPoE. This is typical for UK broadband connections
+## (except "cable"), and common in some other localities as well: ask
+## your ISP if this is you.
+
 { lib, pkgs, config, ...}:
 let
   inherit (lib) mkOption types;