Fix variable declaration in calculateBMI function

Author: MattCarolus10

Sprint-3/3-mandatory-implement/1-bmi.js

@@ -15,7 +15,7 @@
 // It should return a string of their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
-  bmi = weight / (height * height)
+  const bmi = weight / (height * height)
   return bmi.toFixed(1)
   // return the BMI of someone based off their weight and height
 }