feat(CLI): Add category and refine help text

[gaocegege]

The new help text looks like:

 envd - Development environment for data science and AI/ML teams

 Usage:
    envd up --path <path>

    envd run --name <env-name> --command "pip list"

 Build and launch envd environments. Get more information at: https://envd.tensorchord.ai/.
 To get started with using envd, check out the getting started guide: https://envd.tensorchord.ai/guide/getting-started.html.
 
 Advanced Commands:
  pause, p   Pause the envd environment
  resume, r  Resume the envd environment
 Basic Commands:
  build, b          Build the envd environment
  destroy, d        Destroy the envd environment
  envs, env, e      Manage envd environments
  images, image, i  Manage envd images
  run               Spawns a command installed into the environment.
  up, u             Build and run the envd environment
 Management Commands:
  bootstrap  Bootstrap the envd installation
  context    Manage envd contexts
  init, i    Initializes the current directory with the build.envd file
  prune      Clean up the build cache
 Other Commands:
  version, v  Print envd version information

 Global Options:
  --debug     enable debug output in logs (default: false)
  --help, -h  show help (default: false)

Signed-off-by: Ce Gao cegao@tensorchord.ai

[terrytangyuan]

Cool! It would be great if basic commands show up at the top instead of advanced commands. Should bootstrap be in basic commands instead if it will be used by first users?

[gaocegege]

SGTM.

It is hard to reorg the order of the commands with our CLI frameworks. I will investigate how to achieve this.