generate-registry: enable --deep by default

[suzuki-shunsuke]

Feature Overview

Enable --deep by default.

Why is the feature needed?

We should enable --deep in almost all cases.
I asked contributes to use --deep option at many times.
This option should be enabled by default.

Example Code

To keep the compatibility, we don't remove the option --deep in aqua v2, but the option does nothing.
We will remove it at aqua v3.
We will add other options to control the number of API calls.

For example,

• --depth 100
• --count 5

$ aqua gr --depth 100

Reference

[suzuki-shunsuke]

-n 100

--limit -l