fix: Rewrite README links

Author: flovogt

tools/builder/prepare-gh-pages.js

@@ -54,7 +54,7 @@ function getSteps(tutorialDir) {
 	function rewriteLinks(file) {
 		let permalink = file.split("dist/")[1].replace(".md", ".html");
 		let content = `---\npermalink: ${permalink}\n---\n\n${readFileSync(file, { encoding: "utf8"})}`;
-		content = content.replace(/README\.md/g, "README.html");
+		content = content.replace(/README\.md/g, "index.html");
 		content = content.replace(/\.\/packages\//g, "./");
 		content = content.replace(/\[LICENSE\]\([\.\/\w]*\)/g, "[LICENSE](https://github.com/UI5/tutorials/blob/-/LICENSE)");
 		writeFileSync(file, content, { encoding: "utf8" });