Add variable width support for grids

[richmeij]

Following up on #86, it would be very nice if we could also support items of variable widths in a grid setup.

[SuhairZain]

@richmeij This is something important for us as well. Have you found a solution to this?

[dumbmatter]

I've been using #182

[Cryrivers]

@dumbmatter may i ask how do you use #182 to achieve variable width?

[dumbmatter]

In the PR, there is an example added to the storybook.