Command namespaces do not produce meaningful README content

[schlessera]

When scaffolding a README file through the wp scaffold package-readme command, the command namespaces do not produce any meaningful result.

Here's an example output: https://github.com/wp-cli/makepot-command/blob/490b759eb0fe0a4c09d350ba7262d0b0a558248a/README.md#wp-i18n

[Lewiscowles1986]

Do you have ideas about what might be more useful?

I don't know if redundantly listing [sub-command], especially if it is not the default is of any more help.

I do agree it looks misleading, particularly if a namespace command does nothing standalone, but I am unsure as to a fix.