Archive, multitagging, cleanup

Cleaned up the current snippets for consistency and minor problems, added multiple tags to most of them, archived a few.

snippets/lcm.md

@@ -1,6 +1,6 @@
 ### lcm
 
-Returns the least common multiple of two or more numbers/arrays.
+Returns the least common multiple of two or more numbers.
 
 Use the greatest common divisor (GCD) formula and `Math.abs()` to determine the least common multiple.
 The GCD formula uses recursion.
@@ -9,11 +9,11 @@ The GCD formula uses recursion.
 const lcm = (...arr) => {
   const gcd = (x, y) => (!y ? x : gcd(y, x % y));
   const _lcm = (x, y) => x * y / gcd(x, y);
-  return [].concat(...arr).reduce((a, b) => _lcm(a, b));
+  return [...arr].reduce((a, b) => _lcm(a, b));
 };
 ```
 
 ```js
 lcm(12, 7); // 84
-lcm([1, 3, 4], 5); // 60
+lcm(...[1, 3, 4, 5]); // 60
 ```