helm-tool help should be more helpful

[jsoref]

lint and schema should have descriptions

Usage:
  helm-tool [command]

Available Commands:
  completion  Generate the autocompletion script for the specified shell
  help        Help about any command
  inject      generate documentation and inject into existing markdown file
  lint        
  render      render documentation to stdout
  schema      

Flags:
  -h, --help            help for helm-tool
  -i, --values string   values file used to generate the documentation (default "values.yaml")

Use "helm-tool [command] --help" for more information about a command.

schema should explain what it does

Usage:
  helm-tool schema [flags]

Flags:
  -h, --help   help for schema

Global Flags:
  -i, --values string   values file used to generate the documentation (default "values.yaml")

For comparison, helm-tool completion has a description

Generate the autocompletion script for helm-tool for the specified shell.
See each sub-command's help for details on how to use the generated script.

Usage:
  helm-tool completion [command]

Available Commands:
  bash        Generate the autocompletion script for bash
  fish        Generate the autocompletion script for fish
  powershell  Generate the autocompletion script for powershell
  zsh         Generate the autocompletion script for zsh

Flags:
  -h, --help   help for completion

Global Flags:
  -i, --values string   values file used to generate the documentation (default "values.yaml")

Use "helm-tool completion [command] --help" for more information about a command.

lint should explain what it does

Usage:
  helm-tool lint [flags]

Flags:
  -e, --exceptions string   file containing exceptions to the linting rules
  -h, --help                help for lint
  -d, --templates string    templates folder used to lint the values file (default "templates")

Global Flags:
  -i, --values string   values file used to generate the documentation (default "values.yaml")