Update Pluralizer.php

Added plural rules for: common words ending in 'ch' but with 'k' sound use 's' not 'es', torpedo and embargo always use 'es', fungus to fungi (plural of octopus is more proper as octopuses rather than octopi based on many credible sources including Oxford University Press; octopi is etymologically incorrect because it's not from Latin). Added singular rules for: vortices to vortex, fungi to fungus, gallows and headquarters keep the 's' in singular form. Added irregulars for: corpus/corpora, ovum/ova, phenomenon/phenomena, tech/techs (covers biotech, hi-tech, low-tech, nanotech etc.), viscus/viscera. Alphabetized uncountables and added: bison, data, offspring, plankton, swine.