Group multiple text blocks into one background block#819

It would be very helpful to allow grouping multiple text blocks into a single background container.

Currently, when you add a background color to several lines, each line appears as a separate block with gaps between them.

It would be useful if users could select multiple lines or blocks and apply one shared background, creating a single continuous visual block.

This would be especially helpful for things like:

• instructions
• checklists
• highlighted information
• grouped bullet points

Similar to how a callout or database card visually groups content, but usable with normal text blocks.

This would make it easier to visually group related information without needing a database or callout block.