[documentation] get_terms basic usage order

[ramon fincken]

Currently, the ​https://developer.wordpress.org/reference/functions/get_terms/ page shows the deprecated way of calling get_terms for taxonomy "X", followed by the more recent ( 4.5.0 ) way of calling get_terms

I for one mis-copy pasted the first piece of code. Why not switch the two exmple blocks ?
Or even delete the deprecated block of code as 4.5.0 was released in April 2016 ... which is quite a while ago. ( ​https://wordpress.org/support/wordpress-version/version-4-5/ )

[ramon fincken]

57380.20221223.1.patch

[sabernhardt]

The "Prior to 4.5.0" sentence is probably worth keeping, at the end, but removing the old code example could help avoid confusion.

[SergeyBiryukov]

In 55018:

Docs: Remove the legacy example of passing a taxonomy to get_terms().

As of WordPress 4.5, taxonomies should be passed to get_terms() via the taxonomy argument in the $args array:

$terms = get_terms( array(
    'taxonomy'   => 'post_tag',
    'hide_empty' => false,
) );

The legacy way of passing a taxonomy via the function's first parameter was still mentioned in the documentation, causing some confusion.

This commit updates the function documentation to better highlight the currently recommended approach.

Follow-up to [36614].

Props ramon-fincken, sabernhardt, SergeyBiryukov.
Fixes #57380.