Add playbook changer script

bin/playbook-changer.js

@@ -0,0 +1,13 @@
+#!/bin/env node
+
+const scriptName = process.argv[1];
+const environment = process.argv[2];
+
+function helpMessage () {
+	console.log(`${scriptName} - Antora playbook changer script for Decidim documentation
+
+Changes the playbook accordingly to its environment`);
+	console.log(process.env);
+}
+
+helpMessage();

package.json

@@ -2,6 +2,7 @@
   "name": "decidim-documentation",
   "private": true,
   "scripts": {
+    "prebuild": "./bin/playbook-changer.js",
     "build": "antora antora-playbook.yml $@",
     "test": "./bin/test"
   },