Article: https://wordpress.org/documentation/article/gallery-block/

Update for 6.3

• Allow dragging-and-dropping images from the inserter to image blocks. 49673
• Replace "Image size" with "Resolution" in image size controls. 49112
• Update Gallery block to use consistent 40px components. 49101
• Add help text to Gallery Image Size control 49074
• [Inserter - Media tab]: Upload Openverse images when inserted 48501
• add block controls on the inspector 49838

Update for 6.2

• Add toolbar button to add a caption. 47325

Updating for 6.1

• Add padding and margin support to the gallery block. 43965
• Display upload error notices using snackbars. 43946
• Add background color block supports. 43294
• Opt-in to axial (column/row) block spacing controls 41175
• Include image caption when converting a classic block gallery. 40872
• Remove redundant block name from "settings" panels 40275

General

• Make sure all screenshots are relevant to the latest version
• Make sure videos, if any, are up to date
• Add ALT tags for the images
• Make sure the headings are in sentence case
• Convert all reusable blocks to a ‘regular block’.
• Update the changelog at the end of the article

Notes

1. We are not adding detailed updates for the Block settings - Typography, Color, Layout, Dimension and Border and for the More Options setting in the block toolbar. Pls mention the settings included for the block and link to the detailed settings pages instead.
2. Some of the PRs have great videos that can be added to the article.