Backport: mq-max

[stephaniehobson]

Add $mq-max: '(min-width: 1440px)'; to our default media queries. It's been coming up in bedrock.

[stephaniehobson]

It should reference $content-max, obviously - not the hard coded value.

[maureenlholland]

I think this was included in v20 release with protocol tokens package update