Alias for kubectl that works with completion (#12517)

* Alias for kubectl with completion.

Use a shorthand alias for `kubectl` that also works with completion. Using completion is great but typing `kubectl` each time is annoying.

* Update content/en/docs/reference/kubectl/cheatsheet.md

Co-Authored-By: jogy <johann@gyger.name>

content/en/docs/reference/kubectl/cheatsheet.md

@@ -29,6 +29,13 @@ source <(kubectl completion bash) # setup autocomplete in bash into the current
 echo "source <(kubectl completion bash)" >> ~/.bashrc # add autocomplete permanently to your bash shell.
 ```
 
+You can also use a shorthand alias for `kubectl` that also works with completion: 
+
+```bash
+alias k=kubectl
+complete -F __start_kubectl k
+```
+
 ### ZSH
 
 ```bash