Add math mod for lib

src/lib.rs

@@ -3,7 +3,6 @@ use wasm_bindgen::prelude::*;
 extern crate web_sys;
 
 mod utils;
-mod main;
 
 // When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
 // allocator.

src/main.rs

@@ -1,11 +0,0 @@
-fn main() {
-    let a = 10;
-    let b = 5;
-    let sum = sum(a, b);
-
-    println!("Sum of {} + {} = {}", a, b, sum);
-}
-
-pub fn sum(a: i32, b: i32) -> i32 {
-    a + b
-}