Remove donations section

Author: mwilliamson

README.md

@@ -770,10 +770,3 @@ div.aside > h2
 ```
 
 You can nest elements to any depth.
-
-## Donations
-
-If you'd like to say thanks, feel free to [make a donation through Ko-fi](https://ko-fi.com/S6S01MG20).
-
-If you use Mammoth as part of your business,
-please consider supporting the ongoing maintenance of Mammoth by [making a weekly donation through Liberapay](https://liberapay.com/mwilliamson/donate).