Move the -w switch to the configuration file

Update README accordingly.

Woo, I get to remove code.

README.adoc

@@ -56,9 +56,7 @@ Note that for versions of CMake before 2.8.9, you need to prefix `cpack` with
 `fakeroot` or file ownership will end up wrong.
 
 Having the program installed, simply run it with a StarDict '.ifo' file as an
-argument.  If you want the application to watch the X11 primary selection for
-changes and automatically search for the selected text, use the `-w` switch.
-This feature requires GTK+.
+argument.  It is however highly recommended to configure it, see below.
 
 Extensions
 ----------
@@ -78,14 +76,28 @@ with the following.  Note that it is intended for black-on-white terminals.
 center-search = true
 underline-last = false
 hl-common-prefix = true
+watch-selection = true
 
 [Colors]
 header = reverse
+header-active = underline
 search = ul
 even = 16 231
 odd = 16 255
 ....
 
+The `watch-selection` option makes the application watch the X11 primary
+selection for changes and automatically search for selected text.
+This feature requires GTK+ and it will never work on Wayland by its design.
+
+You can also set up some dictionaries to be loaded at startup automatically:
+
+....
+[Dictionaries]
+name1 = ~/path/to/dict.ifo
+name2 = ~/another/dict.ifo
+....
+
 Dictionaries
 ------------
 Unfortunately this application only really works with specific dictionaries.