Add descriptions to patterns in bundled themes

[poena]

Patterns have a parameter called "Description". The description is used in the WordPress interface, to add context for users that can not see or use the pattern preview. For example users of screen readers.

All patterns without the "Inserter" parameter set to "false" or "no", should use the description parameter (These patterns are hidden in the block inserter and do not use the descriptions).

Patterns in bundled themes that are missing descriptions needs to be updated.
Patterns can be registered using the patterns folder or with ​register_block_pattern() and both type of patterns should be updated.

[StringPiggy]

Diff for twentytwentyfour theme

[StringPiggy]

I tested with VoiceOver, would be awesome if can be tested on other screen readers.

[StringPiggy]

Update descriptions for twentytwentyfour

[StringPiggy]

For the twentytwentytwo theme, I noticed most of the title of the pattern is already descriptive. Would a description still be needed in this case?

[StringPiggy]

Add descriptions for twentytwentythree