Checkbox: add 'indeterminate' prop

[tulup-conner]

• I have searched the Issues to see if this bug has already been reported
• I have tested the latest version

Summary

Discussed in #870

^{Originally posted by grasdira July 19, 2023}

Enhancement Suggestion

I think it would be nice to add indeterminate (or isIndeterminate) prop to Checkbox component.

Example:

<Checkbox indeterminate .. />

Context

This is officially supported by DOM elements in all browsers. See https://developer.mozilla.org/en-US/docs/Web/CSS/:indeterminate

[grasdira]

Hi! I'd like to take a shot at solving this issue. Could you assign it to me? Thanks

[tulup-conner]

@grasdira Done, but for the future, you are always welcome to just get started on an issue!

[shereen-fathy]

Hi @grasdira, any progress on this issue?

[grasdira]

Hi @shereen-fathy, yes, I've made some progress on this issue.