added isOperator function

pulled master

readme

Delete .DS_Store

finished for now. added % operator, reorganised html, and made it look pretty

just two lil bugs left to fix

delete function now works and mathOps can handle strings

added 2dp rounding - still working on delete key

added delete key and decimal key

added button disable toggles to prevent consecutive operator input

added negative num and div by zero functionality

updated notes

added to-do

added notes file

equation parsing logic now works