Add less or sass support

[koutoftimer]

This is required for DRY principle, as each tray should be able to contain more than single egg, and for generating set of possible values of data-egg-<tray number>="<eggs positions>" is it better to use less/sass. To support any number of eggs for each tray, there should be following set of data attributes, where egg's positions sorted in ascending order.

data-egg-1="1"
data-egg-1="2"
...
data-egg-1="5"
data-egg-1="1,2"
data-egg-1="1,3"
data-egg-1="1,4"
data-egg-1="1,5"
data-egg-1="2,3"
data-egg-1="2,4"
...