Update README.md. - Add Querystring library note (#1896)

* Update README.md. Querystring libraries note

* Typo in README.md

Co-Authored-By: airs0urce <airs0urce0@gmail.com>

* Update README.md

Co-Authored-By: airs0urce <airs0urce0@gmail.com>

README.md

@@ -639,6 +639,9 @@ axios.post('http://something.com/', querystring.stringify({ foo: 'bar' }));
 
 You can also use the [`qs`](https://github.com/ljharb/qs) library.
 
+###### NOTE
+The `qs` library is preferable if you need to stringify nested objects, as the `querystring` method has known issues with that use case (https://github.com/nodejs/node-v0.x-archive/issues/1665).
+
 ## Semver
 
 Until axios reaches a `1.0` release, breaking changes will be released with a new minor version. For example `0.5.1`, and `0.5.4` will have the same API, but `0.6.0` will have breaking changes.