Change alpha-value-notation for opacity property

[GrimLink]

What steps are needed to reproduce the bug?

Use stylelint version 14 with stylelint-config-standard version 23.

What did you expect to happen?

No error on opacity: 0.8;

What actually happened?

It throws an error on opacities with a number value, while this not supported in every browser yet -> https://developer.mozilla.org/en-US/docs/Web/CSS/opacity

_tests_/index.scss
 59:14  ✖  Expected "0.8" to be "80%"  alpha-value-notation

[GrimLink]

This rule should not be part of this config or should be exclude the css property opacity

[jeddy3]

@GrimLink Thanks for the report.

Let's exclude the opacity property until it lands in the last two version of Safari.

I've labelled the issue as ready to implement. Please consider contributing if you have time.

[GrimLink]

I have time, and the PR is created 😉