List sub-parameter for parameter $feature in DocBlock for current_theme_supports()

[stevenlinx]

The possible values are in the apply_filter DocBlock in function source code:
"Possible values include 'post-formats', 'post-thumbnails', 'custom-background', 'custom-header', 'menus', 'automatic-feed-links', 'html5', 'starter-content', and 'customize-selective-refresh-widgets'."

DevHub:
​https://developer.wordpress.org/reference/functions/current_theme_supports/

[SergeyBiryukov]

In 48490:

Docs: Link to add_theme_support() for the list of supported theme features in current_theme_supports() and related functions.

Props stevenlinx.
Fixes #50657.