Apply new format to snippets and template

snippets/sum.md

@@ -5,7 +5,7 @@ tags: math,array,beginner
 
 Returns the sum of two or more numbers/arrays.
 
-Use `Array.prototype.reduce()` to add each value to an accumulator, initialized with a value of `0`.
+- Use `Array.prototype.reduce()` to add each value to an accumulator, initialized with a value of `0`.
 
 ```js
 const sum = (...arr) => [...arr].reduce((acc, val) => acc + val, 0);