In sqlite's documentation, statement diagrams are provided as images, making them inaccessible for blind users who rely on a program that reads aloud the text on the computer screen. The alternative description for those images look like "syntax diagram create-table-stmt". They're not helpful, I know what the image is, but I don't know what is in the image.

There should be a text alternative for those. The easiest way would be to use the statement definitions from the grammar directly. They could serve as either alt texts or be available separately.