Design CLI subcommands

As follow up on issue #189 and discussion in PR #310:

The current CLI commands are:
`build-wheel`
`clean`
`create-hash`
`create-instance`
`create-secret-key`
`create-wsgi`
`db`
`lang-add-language-catalogue`
`lang-compile-translations`
`lang-extract-translations`
`lang-update-translations`
`run-healthchecks`
`run-tests`
`runner-daemon`
`serve`
`update-docs`
`version`

Where `db` has the sub commands: `adduser`, `create`, `drop`, `export`, `flush`, `load`, `upgrade`.

In this issue I want to discuss the design and reordering of the other commands. I can think of a logical grouping based on 'task' (like 'run', 'create'). That would make:
`geohc create` with subcommands `hash`, `instance`, `secret-key`, `wsgi`
`geohc run` with subcommands `tests`, `healthchecks`, `tests`, `daemon`, `serve`
`geohc lang` with all the language pack commands.

Any further suggestions?