Add message to deprecate the repository

The content of individual lessons was split into seperate repositories. Therefore this lesson no longer has content that is visible in the main geoscripting website and was deprecated

Author: Davidswinkels

README.md

@@ -1,2 +1,4 @@
-PythonWeek
+PythonWeek -- DEPRECATED
+This repository has been deprecated since November 2018, because the Python content of GeoScripting has been split in seperate repositories for each lesson: Refresher, Vector, Raster and Twitter. This repository will be kept as a backup atleast till February 2019.
+
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