Donation Reminder

[LightDestory]

Sporadic advertisements reminding people of the opportunity to donate to support services is somewhat inefficient.

We should implement middleware in the various services that given a probability such as 1 in 15 would attach an advertisement message to the response as well.

The probability should be dynamic and manageable from the outside so that it can be increased and decreased depending on the period (the beginning of the academic year is a good time to increase it in when activity is higher from new users)