Revert "Install for Ubuntu 20.04 (#17869)" (#18089)

This reverts commit 7eb84cf.

Author: Thraka

docs/core/install/includes/package-manager-switcher.md

@@ -1,7 +1,6 @@
 
 > [!div class="op_single_selector"]
 >
-> - [Ubuntu 20.04 - x64](../linux-package-manager-ubuntu-2004.md)
 > - [Ubuntu 19.10 - x64](../linux-package-manager-ubuntu-1910.md)
 > - [Ubuntu 19.04 - x64](../linux-package-manager-ubuntu-1904.md)
 > - [Ubuntu 18.04 - x64](../linux-package-manager-ubuntu-1804.md)

docs/core/install/linux-package-manager-ubuntu-1910.md

@@ -95,7 +95,7 @@ If that doesn't work, you can run a manual install with the following commands.
 
 ```bash
 sudo apt-get install -y gpg
-wget -O- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor -o microsoft.asc.gpg
+wget O- https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor -o microsoft.asc.gpg
 sudo mv microsoft.asc.gpg /etc/apt/trusted.gpg.d/
 wget https://packages.microsoft.com/config/ubuntu/19.10/prod.list
 sudo mv prod.list /etc/apt/sources.list.d/microsoft-prod.list

docs/core/install/linux-package-manager-ubuntu-2004.md

@@ -20,8 +20,6 @@
     href: install/how-to-detect-installed-versions.md
   - name: Linux package managers
     items:
-    - name: Ubuntu 20.04
-      href: install/linux-package-manager-ubuntu-2004.md
     - name: Ubuntu 19.10
       href: install/linux-package-manager-ubuntu-1910.md
     - name: Ubuntu 19.04