definition link of 'base direction' does not points to definition #39
Description
In section 1.3, why is this important?, 'base direction' is marked as definition in third paragraph, but it seems for me this part is not a definition of 'base direction' (rather a state of how important it is). So, it might be better to have some state to define the term.
Also, I feel a link (or mention) to section 3.2 is better to be included, that some may not be noticed that 'base direction' is not a direction of characters/glyphs but a direction of base point for text layout - such as start point of text layout.