Syntax highlighting of Holidays

The following '''holidays''' are observed in [[Centralia]]:

 * '''1^st^ January''' - New Year's Day
 * '''14^th^ February''' - Valentine's Day
 * '''15^th^ March''' - Vernal Equinox (observed)
 * '''20^th^ June''' - Summer Solstice (observed)
 * '''10^th^ August''' - CentraliaPrideDay / PrincessAlice's birthday
 * '''23^rd^ September''' - Autumnal Equinox (observed)
 * '''31^st^ October''' - Halloween
 * '''Fourth Thursday of November''' - National Novembing Day
 * '''25^th^ December''' - Winter Solstice (observed)
 * '''31^st^ December''' - New Year's Eve