Nested arrays of parameters should be parsed as nested lists

[ericdaams]

1. Go to ​https://developer.wordpress.org/reference/functions/register_post_type/
2. Inside the $args parameter, the rewrite list item should have slug, with_front, feeds, pages and ep_mask nested underneath it as a nested list, not as sibling list items.

[coffee2code]

In 2205:

developer.wordpress.org: Display nested hash parameters in a nested fashion.

This just improves the hack used to parse hash parameter notation since the parser doesn't recognize hash parameters as anything more than a bunch of text. Previously it only displayed all hash parameters peer to each other regardless of nesting depth.

For examples of nested hash parameters, see:

• ​https://developer.wordpress.org/reference/functions/register_post_type/
• ​https://developer.wordpress.org/reference/classes/wp_date_query/__construct/

Fixes #1479.