Add manually followed accounts to the database

[eXistenZNL]

Add manually added accounts to the followed.json database to prevent checking this account over and over when in fact we are already following them anyway.

Much like https://github.com/mifi/instauto/issues/33#issuecomment-723217177 but for users that are succesfully followed manually.

I marked them as manual:true so if we feel the need to do something with them later (e.g. don't auto unfollow manually followed accounts) we can simply do this because the data will be already available.

[mifi]

thanks for your pr. I think a consequence of this change is that the bot will automatically start to unfollow these users, and I don't think that is desirable, so need to think this through a bit more

[eXistenZNL]

@mifi Ah, yes! I think the nicest thing to do this is to create two config options for it so people can choose if manually followed account must be unfollowed if they do not follow back, or if they should be eligible for unfollowing at random.

Hold on for an update on this :)