Readme Update

Updated the readme to match the website
Added: Add to watchlist button
Vendor price check

Added: vendor price check
Added: amount check

If the price in CalculatePrice is 0 return 0
Fixed: Sell order bugging out when auction is C.R.E.D.D

Added check for C.R.E.D.D and used proper cancel method
Fixed sell stack price

Added stack multiplier to sell price