Added a few type checking snippets from lodash

snippets/isMap.md

@@ -0,0 +1,13 @@
+### isMap
+
+Checks if value is classified as a Map object.
+
+Use the `instanceof`operator to check if the provided value is a `Map` object.
+
+```js
+const isMap = val => val instanceof Map;
+```
+
+```js
+isMap(new Map()); // true
+```