zsh: kubectl aliases

Adds several kubectl aliases after removing zsh abbrev.

Renames kubectl autocompletion not to start with `kubectl` string for
fast `kube<TAB>` command autocompletion in shell prompt.

zsh/.zshrc

@@ -100,7 +100,9 @@ alias cp='cp -i'
 alias e="$EDITOR"
 alias ee="emacsclient -c -n"
 alias g="git"
-alias kubectl_zsh_setup_autocompletion="source <(kubectl completion zsh)"
+alias kgj="kubectl get jobs"
+alias kgn="kubectl get nodes"
+alias kgp="kubectl get pods"
 alias l="ls -la --color"
 alias ll="ls -l --color"
 alias mv='mv -i'