Moving customBaseFontSize to the end of string.

[mrcordova]

Basically, I am wondering if you would be open to having the custom font size section at the end so instead of mobileFontSize, desktopFontSize, customBaseFontSize, customViewportMin, customViewportMax it would change to mobileFontSize, desktopFontSize, customViewportMin, customViewportMax, customBaseFontSize. The reason for this change is because a user is more likely to change the viewports than the base font size. It would remove unnecessary typing when you want to move from mobile -> tablet to tablet -> desktop.