Add Ubuntu 20.04 distribution link

Author: chad-ramos

WSL/install-win10.md

@@ -62,6 +62,7 @@ wsl --set-default-version 2
 
     - [Ubuntu 16.04 LTS](https://www.microsoft.com/store/apps/9pjn388hp8c9)
     - [Ubuntu 18.04 LTS](https://www.microsoft.com/store/apps/9N9TNGVNDL3Q)
+    - [Ubuntu 20.04 LTS](https://www.microsoft.com/store/apps/9n6svws3rx71)
     - [openSUSE Leap 15.1](https://www.microsoft.com/store/apps/9NJFZK00FGKV)
     - [SUSE Linux Enterprise Server 12 SP5](https://www.microsoft.com/store/apps/9MZ3D1TRP8T1)
     - [SUSE Linux Enterprise Server 15 SP1](https://www.microsoft.com/store/apps/9PN498VPMF3Z)