Correct required Node.js version in readme (#214)

As per the package.json requirement.

Author: Murderlon

README.md

@@ -24,7 +24,7 @@ This is a **Node.js** SDK to make it easy to talk to the
 
 ## Requirements
 
-- [Node.js](https://nodejs.org/en/) version 14 or newer
+- [Node.js](https://nodejs.org/en/) version 18 or newer
 - [A Transloadit account](https://transloadit.com/signup/) ([free signup](https://transloadit.com/pricing/))
 - [Your API credentials](https://transloadit.com/c/template-credentials) (`authKey`, `authSecret`)