Recalculate box heights on window resize
Recalculate box heights on window resize

Closes #10, #19, and #23

jedfoster/Readmore.js,cresqo/cresqo.github.io,daveleee/Readmore.js,cookiespam/terratrix.github.io,daveleee/Readmore.js,jedfoster/Readmore.js