add README and SubmittingPatches

Now that I am the maintainer of the OfflineIMAP project, I need to update some
informations.

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

README.markdown

@@ -0,0 +1,36 @@
+
+# Description
+
+Welcome to the official OfflineIMAP project.
+
+OfflineIMAP is a tool to simplify your e-mail reading. With OfflineIMAP, you can
+read the same mailbox from multiple computers. You get a current copy of your
+messages on each computer, and changes you make one place will be visible on all
+other systems. For instance, you can delete a message on your home computer, and
+it will appear deleted on your work computer as well. OfflineIMAP is also useful
+if you want to use a mail reader that does not have IMAP support, has poor IMAP
+support, or does not provide disconnected operation.
+
+OfflineIMAP works on pretty much any POSIX operating system, such as Linux, BSD
+operating systems, MacOS X, Solaris, etc.
+
+OfflineIMAP is a Free Software project licensed under the GNU General Public
+License. You can download it for free, and you can modify it. In fact, you are
+encouraged to contribute to OfflineIMAP, and doing so is fast and easy.
+
+This software was written by John Goerzen, who retired from maintaining. It is
+now maintained by Nicolas Sebrecht.
+
+# Documentation
+
+The documentation is available in docs/. To generate documentation use
+
+	$ make doc
+
+.
+
+# Mailing list
+
+The user discussion, development and all exciting stuff take place in the
+[mailing list](http://lists.alioth.debian.org/mailman/listinfo/offlineimap-project).
+