doc(contributing): add missing donation link (#11692)

Author: quizhpi

Diff for: .github/CONTRIBUTING.md

@@ -128,6 +128,7 @@ As a pure community-driven project without major corporate backing, we also welc
 
 - [Become a backer or sponsor on Patreon](https://www.patreon.com/evanyou)
 - [Become a backer or sponsor on OpenCollective](https://opencollective.com/vuejs)
+- [One-time donation via PayPal or crypto-currencies](https://vuejs.org/support-vuejs/#One-time-Donations)
 
 ### What's the difference between Patreon and OpenCollective funding?