docs: full refactoring of the MANUAL

Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>

offlineimap.conf

@@ -2,9 +2,27 @@
 
 # This file documents *all* possible options and can be quite scary.
 # Looking for a quick start?  Take a look at offlineimap.conf.minimal.
-# More details can be found in the included user documention, which is
-# also available at: http://docs.offlineimap.org/en/latest/
+# More details can be found at http://offlineimap.github.io.
 
+##################################################
+# Overview
+##################################################
+
+# The default configuration file is "~/.offlineimaprc".
+#
+# OfflineIMAP ships with a file named "offlineimap.conf" that you should copy to
+# that location and then edit.
+#
+# OfflineIMAP also ships a file named "offlineimap.conf.minimal" that you can
+# also try.  It's useful if you want to get started with the most basic feature
+# set, and you can read about other features later with "offlineimap.conf".
+#
+# If you want to be XDG-compatible, you can put your configuration file into
+# "$XDG_CONFIG_HOME/offlineimap/config".
+
+##################################################
+# General definitions
+##################################################
 
 # NOTE 1: Settings generally support python interpolation. This means
 # values can contain python format strings which refer to other values
@@ -31,10 +49,6 @@
 # as it coincides with typical shell expansion strategy.
 
 
-##################################################
-# General definitions
-##################################################
-
 [general]
 
 # This specifies where OfflineIMAP is to store its metadata.
@@ -84,6 +98,8 @@ accounts = Test
 # MachineUI     -- Interactive interface suitable for machine
 #                  parsing.
 #
+# See also offlineimapui(7)
+#
 # You can override this with a command-line option -u.
 #
 #ui = basic