Updated the code to use % operator

[theDevSoham]

This PR fixes #31

The solution

• In the calculate function in script.js firstly modified the regex you used to check for the % operator as well
• I put a code in the same function to check if there's any number after %. If there's no number it'll return the % value of the number. That is it'll divide the number by 100. Else it's getting passed through the eval function which has inbuilt functionality for modulus operations
  
  
  
  

[theDevSoham]

Hey @astush1001 , the latest commit applies the modification requested. Please check. Btw the * sign you see after the % is applied automatically when you press any number key after %. I saw similar functionality in google calculator