18.9.0.0

• Reader Comments: Updated comment threads with a new design and some new capabilities. #17659
• Block editor: Fix issue where editor doesn't auto-scroll so you can see what is being typed. wordpress-mobile/gutenberg-mobile#4299
• Block editor: Preformatted block: Fix an issue where the background color is not showing up for standard themes. wordpress-mobile/gutenberg-mobile#4292
• Block editor: Update Gallery Block to default to the new format and auto-convert old galleries to the new format. wordpress-mobile/gutenberg-mobile#4315
• Block editor: Highlight text: Enables color customization for specific text within a Paragraph block. wordpress-mobile/gutenberg-mobile#4175
• Reader post details: a Comments snippet is now displayed after the post content. #17650