update requirements.txt and add a readme.me

readme.md

@@ -0,0 +1,5 @@
+Install Requirements
+====================
+```
+pip3 install -r requirements.txt
+```

requirements.txt

@@ -1,4 +1,5 @@
 #debian package libatlas3-base required on raspberrypi
+#debian package libpq-dev required for psycopg2
 additional-urwid-widgets
 urwid
 psycopg2