[css-grid] Spec still refers to block-axis baseline.

[javifernandez]

As far as I know, block-axis baseline has been removed from the Grid Layout spec [1]

The following section of the Grid spec still use the "block-axis baseline" baseline term:

https://drafts.csswg.org/css-grid/#grid-order
"'grid-modified document order (grid order) is the order in which grid items are encountered when traversing the grid’s grid cells, in row-major order if calculating the inline-axis baseline, or in column-major order if calculating the block-axis baseline. If two items are encountered at the same time, they are taken in order-modified document order."

I guess it should be removed, for coherence.

[1] #197 (comment)