Docs: Add missing descriptions for `WP_Customize_Header_Image_Control… #22783

Job	Run time
Gutenberg running from src / Linux	9m 37s
Gutenberg running from src / Windows	14m 30s
Gutenberg running from build / Linux	9m 18s
Gutenberg running from src / MacOS	22m 0s
Gutenberg running from build / MacOS	15m 53s
Core running from build / Linux	2m 29s
Core running from src / MacOS	4m 43s
Core running from src / Linux	2m 33s
Core running from src / Windows	4m 27s
Core running from build / MacOS	3m 58s
Core running from build / Windows	3m 55s
Gutenberg running from build / Windows	13m 43s
Slack Notifications / Prepare notifications	6s
Slack Notifications / Success notifications	3s
Slack Notifications / Cancelled notifications	-229s
Slack Notifications / Fixed notifications	-235s
Failed workflow tasks	-245s
Slack Notifications / Failure notifications	-284s
	1h 30m 42s

Provide feedback