Merge pull request #52 from troglobit/doc-updates

Doc updates

README.md

 - [Introduction](#introduction)
 - [Examples](#examples)
 - [Usage](#usage)
-  - [Operation modes](#operation-modes)
-  - [Value modes](#value-modes)
-  - [Target](#target)
-  - [Field](#field)
-  - [Controller modes](#controller-modes)
+  - [Commands](#commands)
+  - [Options](#options)
 - [Installation](#installation)
   - [Arch Linux](#arch-linux)
   - [Fedora](#fedora)
 * Automatically detects the best controller
 * Possibility to set a minimum brightness value
 
-Let's get started with a few examples, for details, see below for the
-full description of the different commands, options and how to access
-different controllers.
+Let's get started with a few examples!  See the following sections for
+the detailed descriptions of all available commands, options and how to
+access different controllers.
 
 
 Examples

light.1

 Read values, Errors, Warnings, Notices
 .El
 .El
+.Sh FILES
+When run in its classic SUID root mode
+.Nm
+caches settings and current brightness in
+.Pa /etc/light .
+In its non-priviliged mode of operation the
+.Pa ~/.cache/light
+directory is used instead.
 .Sh AUTHORS
 Copyright \(co 2014 Fredrik Haikarainen
 .Pp