Set the alignment of the gutter renderer.
Both xalign and yalign can be -1, which means the values will not be changed (this allows changing only one of
the values).
xalign is the horizontal alignment. Set to 0 for a left alignment. 1 for a right alignment. And 0.5 for centering the cells.
yalign is the vertical alignment. Set to 0 for a top alignment. 1 for a bottom alignment.
| this | |
| xalign |
the x-alignment |
| yalign |
the y-alignment |