This is beautiful. I wanted more content like this, and supporting Kahn Academy made me want to support this also.

They have a Patreon page. If you like what's here already and want it to grow - you should donate too!

https://www.patreon.com/mathigon

Just a couple of dollars from each of us is likely to make a huge difference to such a volunteer effort!

There are more options here : https://mathigon.org/donate

(When I posted this, Patreon had only 5 supporters - can you help too?)