Updated README buttons to tell we're not compatible with 2.3.2 yet

Author: 0livier

README.md

@@ -3,6 +3,7 @@ Algolia Search for Magento 2
 
 ![Latest version](https://img.shields.io/badge/latest-1.11.2-green.svg)
 ![Magento 2](https://img.shields.io/badge/Magento-%3E=2.1-blue.svg)
+![Magento 2](https://img.shields.io/badge/Magento-%3C%202.3.2-blue.svg)
 ![PHP >= 5.6.5](https://img.shields.io/badge/PHP-%3E=5.6-green.svg)
 [![CircleCI](https://circleci.com/gh/algolia/algoliasearch-magento-2/tree/master.svg?style=svg)](https://circleci.com/gh/algolia/algoliasearch-magento-2/tree/master)