Remove donation section in favor of GitHub Sponsor button

Author: rmm5t

README.markdown

@@ -9,23 +9,6 @@ Launchy have made this method of keyboard entry a popular one. It's time to
 bring this same functionality to web controls. FlexSelect does that for select
 boxes.
 
----
-
-**How You Can Help**
-
-[![Square Cash](http://img.shields.io/badge/square%20cash-$rmm5t-brightgreen.svg)][square]
-[![Gratipay](http://img.shields.io/gratipay/rmm5t.svg)][gratipay]
-[![Book a Codementor session](http://img.shields.io/badge/codementor-book%20a%20session-orange.svg)][codementor]
-
-If you like this project, [buy me a coffee][square], [donate via Gratipay][gratipay], or [book a session with me on Codementor][codementor].
-
-Bitcoin: `1rmm5tv6f997JK5bLcGbRCZyVjZUPkQ2m`
-
-[square]: https://cash.me/$rmm5t "Donate to rmm5t for open source!"
-[gratipay]: https://gratipay.com/rmm5t/ "Donate to rmm5t for open source!"
-[bitcoin]: bitcoin:1rmm5tv6f997JK5bLcGbRCZyVjZUPkQ2m?amount=0.01&label=Coffee%20to%20rmm5t%20for%20Open%20Source "Buy rmm5t a coffee for open source!"
-[codementor]: https://www.codementor.io/rmm5t?utm_campaign=profile&utm_source=button-rmm5t&utm_medium=shields "Book a session with rmm5t on Codementor!"
-
 ## Usage
 
 First, load [jQuery](http://jquery.com/), the