Save session on connect and fix some typos

The session is saved upon connecting with the hope to make
sure that the authorization key gets saved to disk before
the next run.

telethon_examples/assistant.py

@@ -351,7 +351,7 @@ async def handler(event):
         for i in range(1, 4)
     ]
     what = max(rates, key=lambda t: t[1])
-    if what[1] < 0.7:
+    if what[1] < 0.75:
         return
 
     name = what[0]