Short array syntax used in WP_HTML_Tag_Processor docs/examples

[aristath]

Docs for methods in the WP_HTML_Tag_Processor object use a short array syntax. However, that syntax is not allowed in WP.

Trac ticket: https://core.trac.wordpress.org/ticket/57691

This is a backport of ​https://github.com/WordPress/gutenberg/pull/47958

[aristath]

Done in Gutenberg in ​https://github.com/WordPress/gutenberg/pull/47958. The PR attached above is a backport.

[SergeyBiryukov]

In 55304:

Docs: Replace short array syntax in WP_HTML_Tag_Processor documentation.

Per ​WordPress PHP Coding Standards:

Using long array syntax ( array( 1, 2, 3 ) ) for declaring arrays is generally more readable than short array syntax ( [ 1, 2, 3 ] ), particularly for those with vision difficulties. Additionally, it’s much more descriptive for beginners.

Arrays must be declared using long array syntax.

Original PR from Gutenberg repository:

• ​#47958 Docs: Don't recommend using short array syntax in WP_HTML_Tag_Processor

Follow-up to [55203], [55206].

Props aristath, poena.
Fixes #57691.

Thanks for the PR! Merged in r55304.