Axum API with Swagger UI

• create swagger UI
• add POST and GET

todo:

• take 2 params : i32, i32 and return result in JSON
  
• eg.Currently this is returning JSON <QueryParams>

  pub async fn query_params(Query(query): Query<QueryParams>) -> Json<QueryParams> {
      Json(query)
  }
  

• Add in a function to return i32 from a calculation of input param1 and input param2
• link with SQLX