add example config

config.py.example

@@ -0,0 +1,7 @@
+import os
+import subprocess
+
+class Config:
+    SECRET_KEY = os.environ.get('SECRET_KEY') or subprocess.check_output(['pwgen', '20', '1'])
+    DATA_DIR   = os.environ.get('DATA_DIR') or '/home/orange/devel/prolefeeder/tmp'
+    MAX_LENGTH = os.environ.get('MAX_LENGTH') or 180