Add mustache cache example

My results with cached mustache is a lot better:
===NATIVE===
Simple Test: 146.19399414062ms, 310.4byte PHP, 0byte System
Loop Test: 136.38813476563ms, 236byte PHP, 26214.4byte System


===MUSTACHE===
Simple Test: 395.30563964844ms, 23620.8byte PHP, 52428.8byte System
Loop Test: 780.89516601563ms, 2816byte PHP, 0byte System


===MUSTACHE CACHED===
Simple Test: 152.10305175781ms, 200byte PHP, 0byte System
Loop Test: 459.80954589844ms, 200byte PHP, 0byte System


===TWIG===
Simple Test: 176.93303222656ms, 131239.2byte PHP, 157286.4byte System
Loop Test: 544.47629394531ms, 15188byte PHP, 0byte System


===SMARTY===
Simple Test: 264.49147949219ms, 260452byte PHP, 262144byte System
Loop Test: 327.04890136719ms, 6908.8byte PHP, 0byte System