Made calculation of POS reward dynamic and added noscript tag

This commit makes the POS reward calculation dynamic. Instead of entering the desired values into the \<input\> tags and pressing the "Calculate POS Reward" button, now you can simply type what value you want and it will dynamically update the reward table as you're typing, or when the \<input\> loses focus.

Additionally, I added two \<noscript\> tags to let anyone visiting the page without JavaScript know that they need to enable it in order to use the POS calculator.