* 🐛 Enable `0.x` with negative margins @ v4
I set it as below, but no negative margin was added.
`$spacers: (0\.5: ($spacer * .125));`
After investigating, it seems that `0 \ .5` is also evaluated as 0.
So I changed it to string comparison.
HTML example: `<img class="mt-n0.5">`
* 💚 Clear CI errors