chore(lib): copy readme for prod build

Author: marcjulian

package.json

@@ -11,7 +11,7 @@
     "lint": "ng lint",
     "e2e": "ng e2e",
     "plugin:build": "ng build ngxs-ionic-router-plugin",
-    "plugin:prod": "ng build ngxs-ionic-router-plugin --prod",
+    "plugin:prod": "ng build ngxs-ionic-router-plugin --prod && cp README.md dist/@fivethree/ngxs-ionic-router-plugin/.",
     "version": "conventional-changelog -p angular -i CHANGELOG.md -s"
   },
   "private": true,