Add modal options with responsive.

[hieusmiths]

• I have searched the issues of this repository and believe that this is not a duplicate.

What problem does this feature solve?

Now, assume you have a modal, when on the desktop it will has width is 60%
Then when resize viewport down to 768px you want it has width is 95%.

What does the proposed API look like?

I think we can add witdh option is an object like here:

width={{sm: 40%, md: 55%}}
Thank so much team

[nvmnghia]

bump this