In card description and comments you can use the Tab key to insert 4 spaces, and use Shift-Tab to delete 4 spaces.
The left and right arrow keys skip 4 spaces at once, and the backspace deletes 4 spaces at once.
If you select multiple lines the Tab and Shift-Tab key will indent or re-indent all selected lines at once.
This makes editing more versatile (especially in code blocks), and the feature is automatically enabled on all boards.