Fix spelling and capitalization within wp-includes/load.php

[stevegrunwell]

When tracking something down this morning, I noticed that "administrative" was misspelled as "admininstrative" in the DocBlock for is_admin().

[stevegrunwell]

Fix the spelling of "administrative" in the DocBlock for is_admin(), along with minor capitalization fixes ("XML" and "PHP")

[welcher]

Thanks for the patch @stevegrunwell! This looks good to me to get committed.

[SergeyBiryukov]

In 46759:

Docs: Correct spelling and capitalization in wp-includes/load.php:

• Fix typo in is_blog_admin() description.
• Capitalize PHP correctly in enable_wp_debug_mode_checks filter description.
• Capitalize XML correctly in wp_is_xml_request() return value description.

Props stevegrunwell.
Fixes #48771.

[SergeyBiryukov]

Going to move this to 5.4, as it's not a regression in 5.3, and we're trying to keep the number of changed files in minor releases to a minimum, due to ​reliability concerns for background updates.

[SergeyBiryukov]

In 46760:

Docs: Adjust wp_is_json_request() and wp_is_xml_request() return value descriptions for consistency.

See #48771, #48303.