Rewrite Shell Friends to be a beginner guide to the shell

Author: danielbachhuber

index.md

@@ -33,7 +33,7 @@ $ wp transient delete --all
 Success: 34 transients deleted from the database.
 ```
 
-For a more complete introduction to using WP-CLI, read the [Quick Start guide](https://wp-cli.org/docs/quick-start/).
+For a more complete introduction to using WP-CLI, read the [Quick Start guide](https://wp-cli.org/docs/quick-start/). Or, catch up with [shell friends](https://wp-cli.org/docs/shell-friends/) to learn about helpful command line utilities.
 
 Already feel comfortable with the basics? Jump into the [complete list of commands](https://wp-cli.org/commands/) for detailed information on managing themes and plugins, importing and exporting data, performing database search-replace operations and more.