Add sponsorship information

Author: chrisballinger

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: chrisballinger

README.md

@@ -17,9 +17,11 @@ If you are an open source project, please [contact us](mailto:chris@chatsecure.o
 ### Cost for End Users
 
 Downloading the ChatSecure app is **100% free** because it is important that all people around the world have unrestricted access to privacy tools.
-However, developing and supporting this project is hard work and costs real money. Please help support the development of this project! We now also accept Bitcoin via Coinbase!
+However, developing and supporting this project is hard work and costs real money. Please help support the development of this project!
 
-[![bitcoin coinbase donation](https://chatsecure.org/images/bitcoin_donate.png)](https://coinbase.com/checkouts/1cf35f00d722205726f50b940786c413) [![paypal donation](https://chatsecure.org/images/paypal_donate.png)](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=F9SM36SQY5EN8) 
+* [GitHub Sponsors](https://github.com/sponsors/chrisballinger)
+* [PayPal](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=F9SM36SQY5EN8)
+* [Bitcoin](bitcoin:bc1qrpswdcrga6w74sm08wy9mult6jp7zt5vjtx0zx?message=ChatSecure%20Donations) `bc1qrpswdcrga6w74sm08wy9mult6jp7zt5vjtx0zx`
 
 
 ## Localization