add --slide-width/height css variables
add --slide-width/height css variables

rbtcollins/reveal.js,tehfedaykin/10CommandmentsofCommunityOrganizing,10xEngineer/reveal.js,dbs/reveal.js,hakimel/reveal.js,dbs/reveal.js,siddhartha-gadgil/presentations,lvh/reveal.js,Jean85/reveal.js,hakimel/reveal.js,seefood/DIYHolidays,rbtcollins/reveal.js,10xEngineer/reveal.js,seefood/DIYHolidays,maximesinclair/presentations,lvh/reveal.js,rbtcollins/reveal.js,jayramj/agile-retro,tehfedaykin/10CommandmentsofCommunityOrganizing,siddhartha-gadgil/presentations,kenkunz/js-crash-course,Jean85/reveal.js,rbtcollins/reveal.js,siddhartha-gadgil/presentations,jayramj/agile-retro,rbtcollins/reveal.js,rbtcollins/reveal.js,kenkunz/js-crash-course,maximesinclair/presentations