Complete README.md with interesting parts.

README.md

@@ -7,4 +7,30 @@ configuration. I don't recommend using it by you can pick anything you
 need in it.
 
 I rely on machine hostname for some configuration parts (see
-`start.lua`) for the most important part.
+`rc/start.lua`) for the most important part.
+
+Here some of the things you may be interested in:
+
+ - It is modular. I am using `config` as a table to pass different
+   things between "modules".
+ - In `rc/start.lua`, there is a `xrun` function which runs a program
+   only if it is not already running. Instead of relying on tools like
+   `ps`, it looks at the list of the connected clients with
+   `xwininfo`. Seems reliable.
+ - I use a light transparency effect to tell if a window has the focus
+   or not. It needs a composite manager. I have chosen `unagi` for
+   this (packaged in Debian).
+ - I use a Python script `bin/build-wallpaper` to build the wallpaper
+   to be displayed. There is a random selection and it works with
+   multihead setup. It seems that classic tools are now able to change
+   the wallpaper per screen and therefore, the script may seem a bit
+   useless but I keep it.
+ - I am using `xautolock` + `i3lock` as a screensaver. Nothing fancy
+   but I reuse the wallpaper built above.
+ - In `rc/theme.lua`, you may be interested by the way I configure
+   GTK2 and GTK3 to have an unified look. It works and it does not
+   need `gnome-control-center`.
+ - I am sharing tags between screen with
+   [sharetags](http://awesome.naquadah.org/wiki/Shared_tags). I am
+   also giving names to tags: I access them with something like
+   `config.tags.emacs`.