Command Help

Command help is shown when a user adds the `--help` flag after a command. For Commando, I want to separate concerns between registering commands and command groups and their help information. Developers will define help in help.yaml file then commando will load the file and add help to the commands.

The yaml file should have the following format

```yaml
parent child grand-child
type: command
short-summary: "grand-child help"
parameters:
- name: --body
short-summary: "itemBody"
long-summary: |
Usage: --body content=XX content-type=XX
content: The content of the item.
- name: --end
short-summary: "dateTimeTimeZone"
long-summary: |
Usage: --end date-time=XX time-zone=XX
```

Running `parent child grand-child --help` will result in the output below

```sh
usage: parent child grand-child [-h|--help] --body --end

Arguments:

-h --help Print help information
--body itemBody
--end dateTimeTimeZone
```