add a README

README

+
+imap-autoconfig
+===============
+
+This little WSGI application is used to serve the config-v1.1.xml file
+which Thunderbird looks for when attempting to auto-configure the
+connection parameters for a new email account.  See the Mozilla
+documentation at:
+
+https://developer.mozilla.org/en-US/docs/Thunderbird/Autoconfiguration
+
+To run this application, point your "autoconfig.*" domains at it.
+
+
+