postinstall is more widely known than prepare

package.json

@@ -8,7 +8,7 @@
         "url": "git://github.com/codegouvfr/keycloakify-starter.git"
     },
     "scripts": {
-        "prepare": "copy-keycloak-resources-to-public",
+        "postinstall": "copy-keycloak-resources-to-public",
         "start": "react-scripts start",
         "build": "react-scripts build",
         "build-keycloak-theme": "yarn build && keycloakify",