Update containers.md

Author: Chuxel

docs/remote/containers.md

@@ -65,7 +65,6 @@ Let's start out by using a sample project to try things out.
     git clone https://github.com/Microsoft/vscode-remote-try-java
     git clone https://github.com/Microsoft/vscode-remote-try-dotnetcore
     git clone https://github.com/Microsoft/vscode-remote-try-php
-    git clone https://github.com/Microsoft/vscode-remote-try-ruby
     git clone https://github.com/Microsoft/vscode-remote-try-rust
     git clone https://github.com/Microsoft/vscode-remote-try-cpp
     ```