Support donation-per-work

[jelv]

Some creators and backers prefer donation-per-work with an maximum cap for each month like Patreon uses.

Because some months I focus on other things and finish less work, and other months I am in a financially tight spot but have lots of time. Also, some of my patrons would rather reward me for work I finish than just pay a flat rate. I tried self-rolled, monthly subscriptions ages ago and nobody signed up. Patreon offered pay-per-work and people do sign up for that. At the moment, I have a stable income through Patreon by composing something every month, and extra income if I need it by composing two or three things that month, without having to do extra sales and marketing work. (And patrons can cap their monthly pledge amount, so I know I won't bankrupt them.) Related discussion: https://mastodon.xyz/@artsyhonker/99139225711681045