Merge pull request docker#13543 from thaJeztah/remove_ubuntu_20.10

engine: remove Ubuntu 20.10 "Groovy" (EOL: 2021-07-22)

Author: usha-mandya

engine/install/ubuntu.md

@@ -28,7 +28,6 @@ To install Docker Engine, you need the 64-bit version of one of these Ubuntu
 versions:
 
 - Ubuntu Hirsute 21.04
-- Ubuntu Groovy 20.10
 - Ubuntu Focal 20.04 (LTS)
 - Ubuntu Bionic 18.04 (LTS)