text: Title: Handle messages from a group
  Body: Hello everyone,
  
  How can I handle messages from a group? (I didn't receive messages in the `process_messages`)
  
  - created a bot
  - set privacy mod to DISABLED at BotFather:
  ```
  > User
  /setprivacy
  
  > BotFather
  Choose a bot to change group messages settings.
  
  > User
  @name_bot
  
  > BotFather
  'Enable' - your bot will only receive messages that either start with the '/' symbol or mention the bot by username.
  'Disable' - your bot will receive all messages that people send to groups.
  Current status is: DISABLED
  
  > User
  Disable
  
  > BotFather
  Success! The new status is: DISABLED. /help
  ``` 
  - create a group
  - added the bot to the group as an admin
  - ran the code:
  ```python
  from aiogram import Bot, Dispatcher, executor, types
  
  bot = Bot(token="<API token>")
  dp = Dispatcher(bot)
  
  
  @dp.message_handler(chat_type=[types.ChatType.GROUP, types.ChatType.CHANNEL])
  async def process_messages(msg: types.Message):
      ...  # TODO: to process the message
  
  executor.start_polling(dp)
  ```
  
  Permissions of the bot in the channel:
  ![image](https://user-images.githubusercontent.com/77075714/111037742-2c358880-842e-11eb-86bf-b3ab014d33c1.png)