Store human readable chat history

[r4rdsn]

As of now bot only has standard stdout aiogram logger of incoming updates, which docker takes care of. It can be useful for debugging purposes, but is not quite readable, as it doesn't save the type and structure of update (i. e. message or keyboard query). Storing chat history in some human readable format will allow to analyze user interactions and shape further development.

[r4rdsn]

All updates get saved in the database since 3139422. Now the remaining part of the issue is making an interface to get this stored data.