Get rid of client.loop

Instead, use the asyncio-intended way of implicit loop.

readthedocs/concepts/full-api.rst

@@ -74,7 +74,7 @@ Or we call `client.get_input_entity()
     async def main():
         peer = await client.get_input_entity('someone')
 
-    client.loop.run_until_complete(main())
+    asyncio.run(main())
 
 .. note::
 

readthedocs/concepts/sessions.rst

@@ -156,8 +156,8 @@ you can save it in a variable directly:
 .. code-block:: python
 
     string = '1aaNk8EX-YRfwoRsebUkugFvht6DUPi_Q25UOCzOAqzc...'
-    with TelegramClient(StringSession(string), api_id, api_hash) as client:
-        client.loop.run_until_complete(client.send_message('me', 'Hi'))
+    async with TelegramClient(StringSession(string), api_id, api_hash).start() as client:
+        await client.send_message('me', 'Hi')
 
 
 These strings are really convenient for using in places like Heroku since