add note about being an alpha

aqt/__init__.py

@@ -245,6 +245,8 @@ environment points to a valid, writable folder.""")
     # remaining pm init
     pm.ensureProfile()
 
+    print("This is an ALPHA build - please do not package it up for Linux distributions")
+
     # load the main window
     import aqt.main
     mw = aqt.main.AnkiQt(app, pm, args)