refactor(create-docusaurus): add future.v4 flag to init templates (#10871)

Author: slorber

packages/create-docusaurus/templates/classic-typescript/docusaurus.config.ts

@@ -9,6 +9,11 @@ const config: Config = {
   tagline: 'Dinosaurs are cool',
   favicon: 'img/favicon.ico',
 
+  // Future flags, see https://docusaurus.io/docs/api/docusaurus-config#future
+  future: {
+    v4: true, // Improve compatibility with the upcoming Docusaurus v4
+  },
+
   // Set the production url of your site here
   url: 'https://your-docusaurus-site.example.com',
   // Set the /<baseUrl>/ pathname under which your site is served

packages/create-docusaurus/templates/classic/docusaurus.config.js

@@ -14,6 +14,11 @@ const config = {
   tagline: 'Dinosaurs are cool',
   favicon: 'img/favicon.ico',
 
+  // Future flags, see https://docusaurus.io/docs/api/docusaurus-config#future
+  future: {
+    v4: true, // Improve compatibility with the upcoming Docusaurus v4
+  },
+
   // Set the production url of your site here
   url: 'https://your-docusaurus-site.example.com',
   // Set the /<baseUrl>/ pathname under which your site is served