Add Mullvad VPN (#1299)

* Update README.md

* Update README.md

README.md

@@ -867,7 +867,7 @@ Any comments, suggestions? [Let us know!](https://github.com/jaywcjlove/awesome-
 * [V2rayU](https://github.com/yanue/V2rayU) - Macos client based on v2ray. [![Open-Source Software][OSS Icon] ![Freeware][Freeware Icon]](https://github.com/yanue/V2rayU)
 * [Windscribe](https://windscribe.com) - Gives 10GB free bandwidth monthly on the spot and gives limited server location options (for users on free plan). Connection also takes very less time.
 * [ClashX](https://github.com/yichengchen/clashX) - A rule-based proxy for Mac based on Clash. [![Open-Source Software][OSS Icon]](https://github.com/yichengchen/clashX)![Freeware][Freeware Icon]
-* [Mullvad VPN](https://mullvad.net) - Privacy focused VPN that requires no personal information for use, keeps no logs, and allows payments with Bitcoin Cash, Monero and more.
+* [Mullvad VPN](https://mullvad.net) - Privacy focused VPN that requires no personal information for use, keeps no logs, and allows payments with Bitcoin Cash, Monero and more. [![Open-Source Software][OSS Icon]](https://github.com/mullvad/mullvadvpn-app)
 * [Outline](https://getoutline.org/) - Outline makes it easy to create a VPN server, giving anyone access to the free and open internet. [![Open-Source Software][OSS Icon]](https://github.com/Jigsaw-Code) ![Freeware][Freeware Icon]
 
 ## Utilities