const add = a => b => a + b;
add(2)(3); // 5Currying converts a multi-argument function into a chain of single-argument functions.
Currying is a technique of translating a function that takes multiple arguments into a sequence of functions that each take a single argument.
Challenge: Create a curried add function using arrow functions. Instead of add(a, b), it should be called as add(a)(b).