Prerequisites

• I have searched for duplicate or closed feature requests
• I have read the contributing guidelines

Proposal

Classes for setting Flex gap, for example:

• flex-gap-3 - sets the gap to be the same as mb-3
• flex-gap-4-2 - sets the vertical gap to be the same as mb-4 and horizontal to be the same as mb-2

Motivation and context

Flex gap is useful when using flex and supported by modern browsers: https://caniuse.com/flexbox-gap