New UX: raise the limit of columns in one row to 12

[M.Kierepka]

As a Page Builder, I need more than 4 columns on the New UX Board.

Currently, in New UX, there is a limit of 4 columns in a single row. But when designing a page, Page Builder can easily see, that there should be possibility to have up to 12 columns - that's how Board is divided. I know that currently, when you place card on the grid, whole row is automatically divided in equal parts (and it's not achievable for 5, 7, 8, 9, 10 & 11 columns), but it shouldn't stop us from placing more cards - they just don't have to be equally spaced.