Improve list filtering functions documentation

[ribaricplusplus]

Creating this ticket as a "pull request" for some minor documentation improvements for wp_filter_object_list and wp_list_filter to make it more obvious what they do without reading code.

[desrosj]

Hi @ribaricplusplus,

Thanks for this patch! My apologies that this one has not received a review yet. Today is feature freeze for WordPress 5.8. I'm going to leave this in the milestone because it only touches inline documentation. Changes to documentation can be made up until the RC phase of the cycle. If this doesn't receive attention in the next week, we'll punt it to 5.9 and address it in the next release.

[SergeyBiryukov]

In 51044:

Docs: Improve documentation for wp_list_filter() and wp_filter_object_list().

This should make the purpose and behavior of these functions more obvious without reading the code.

Props ribaricplusplus.
Fixes #52808.

[ribaricplusplus]

Thanks for merging :)

[SergeyBiryukov]

Thanks for the ticket and the patch! :)