docs: added documentations and help message for setup completions when used as kubectl plugin

[nekomeowww]

Close #786.

Summary

• Added a new hack script to proxy arguments to Cobra's _completion command
• Translated documentation for Simplified Chinese
• Refined the original documentations for English
• Refined the help message of completion sub command, for better reading experience and instructions
• Added instructions about how to configure and setup the completions for kubectl kc

Demo

completion --help now prints:

❯ ./main completion --help
To load completions for kubecm cli:

For Bash users:

  # To load completions for the current session, execute once:
  source <(kubecm completion bash)

  # To load completions for each session, execute once (you will need to start a new
  # shell for this setup to take effect.):

  # Linux:
  kubecm completion bash > /etc/bash_completion.d/kubecm

  # macOS:
  kubecm completion bash > /usr/local/etc/bash_completion.d/kubecm

For Zsh users, execute:

  # If shell completion is not already enabled in your environment,
  # you will need to enable it.  You can execute the following once:

  echo "autoload -U compinit; compinit" >> ~/.zshrc

  # To load completions for each session, execute once (you will need to start a new
  # shell for this setup to take effect.):
  kubecm completion zsh > "${fpath[1]}/_kubecm"

For fish users, execute:

  # Load completions for the current session, execute once:
  kubecm completion fish | source

  # Load completions for each session, execute once (you will need to start a new
  # shell for this setup to take effect.):
  kubecm completion fish > ~/.config/fish/completions/kubecm.fish

For PowerShell users, execute:

  # To load completions for the current session, execute once:
  kubecm completion powershell | Out-String | Invoke-Expression

  # To load completions for every new session, run:
  kubecm completion powershell > kubecm.ps1
  # and source this file from your PowerShell profile.

---

To load completions for kubectl kc when used as kubectl plugin:

1. Use the following command as one-liner to add the completion to the current shell session:

  mkdir -p ~/.config/.kubectl-plugin-completions
  cat <<EOF >~/.config/.kubectl-plugin-completions/kubectl_complete-kc
  #!/usr/bin/env sh

  # Call the __complete command passing it all arguments
  kubectl kc __complete "\$@"
  EOF
  chmod +x ~/.config/.kubectl-plugin-completions/kubectl_complete-kc

2. Append the directory to the $PATH environment variable.

For Bash users, execute:

  echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.bashrc

For Zsh users, execute:

  echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.zshrc

For fish users, execute:

  fish_add_path ~/.config/.kubectl-plugin-completions

---

Usage:
  kubecm completion [bash|zsh|fish|powershell] [flags]

Aliases:
  completion, c

Flags:
  -h, --help   help for completion

Global Flags:
      --config string   path of kubeconfig (default "/Users/neko/.kube/config")
  -m, --mac-notify      enable to display Mac notification banner
      --ui-size int     number of list items to show in menu at once (default 4)

And kubectl kc now works:

Test & Verifications

• bash
• zsh
• fish
• PowerShell (on macOS)

[the-label-bot]

The Label Bot has predicted the following:

Category	Value	Confidence	Applied Label
Kind	feature	0.911	✔️
Size	L	0.980	✔️

[sunny0826]

🎉 LGTM, Thanks for your contribute !

[sunny0826]

Sorry the Review is a little late, I've just recently taken a little time out.