Add composer plugins.

README.md

 *Extras related to dependency management.*
 
 * [Composed](https://github.com/joshdifabio/composed) - A library to parse your project's Composer environment at runtime.
-* [Composer Merge Plugin](https://github.com/wikimedia/composer-merge-plugin) - A composer plugin to merge several composer.json files.
+* [Composer Merge Plugin](https://github.com/wikimedia/composer-merge-plugin) - A composer plugin to merge several `composer.json` files.
+* [Composer Nomralize](https://github.com/ergebnis/composer-normalize) - A plugin for normalising `composer.json` files. 
 * [Composer Patches](https://github.com/cweagans/composer-patches) - A plugin for Composer to apply patches.
 * [Composer Require Checker](https://github.com/maglnet/ComposerRequireChecker) - CLI tool to analyze composer dependencies and verify that no unknown symbols are used in the sources of a package.
 * [Composer Unused](https://github.com/composer-unused/composer-unused) - A CLI Tool to scan for unused composer packages.