change javascript dummy page to markdown and explain page creation in readme file

README.md

@@ -31,3 +31,13 @@ GIT_USER=<Your GitHub username> USE_SSH=true yarn deploy
 ```
 
 If you are using GitHub pages for hosting, this command is a convenient way to build the website and push to the `gh-pages` branch.
+
+## Create a new page
+
+We have two different ways to create a new page, in JavaScript, or, in Markdown: 
+
+- If we don't need a specific layout, we recommend to create a page in Markdown, with `.md` extention.
+- If we need to specific layout, create a page in JavaScript with `.js` extention.
+
+This offers a better return on investment because the Markdown (`.md`) is faster to do.
+

src/pages/dummy_page.js

-import React from "react";
-import Layout from "@theme/Layout";
-
-function Dummy() {
-  return (
-    <Layout title="Bonjour">
-      <div
-        style={{
-          display: "flex",
-          justifyContent: "center",
-          alignItems: "center",
-          height: "50vh",
-          fontSize: "20px",
-        }}>
-        <p>
-          Editez <code>pages/dummy.js</code> et sauvegardez pour recharger.
-        </p>
-      </div>
-    </Layout>
-  );
-}
-
-export default Dummy;

src/pages/dummy_page.md

+---
+title: dummy
+description: page factice
+---
+
+# Page factice
+
+Page factice penser à créer une vraie page !