[Feature] laf-cli support shell autocompletion

### Search before asking

- [X] I had searched in the [issues](https://github.com/labring/laf/issues?q=is%3Aissue) and found no similar issues.

### Feature Request

### Background

Now we already have laf-ci, here is the [doc](https://doc.laf.run/guide/cli/), and here is the [code of cli](https://github.com/labring/laf/tree/main/cli).

When using the command line, we really look forward to it being able to autocomplete automatically!

## What to do

You can add a `completion` command to generate an automatic completion script, and also add documentation to instruct users on how to use the completion command in bash, zsh, and fish.

You can refer to the command completion documentation of K8s: https://kubernetes.io/docs/tasks/tools/install-kubectl-macos/#enable-shell-autocompletion

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!