diff --git a/.github/gitgraph/branching-scheme.html b/.github/gitgraph/branching-scheme.html
index bae1ee2b5..2af1dbf13 100644
--- a/.github/gitgraph/branching-scheme.html
+++ b/.github/gitgraph/branching-scheme.html
@@ -1,17 +1,26 @@
 <!DOCTYPE html>
-<html>
-<head>
-<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/gitgraph.js/1.11.4/gitgraph.min.css" />
-<style>
-	body {
-		margin: 0;
-		padding: 0;
-	}
-</style>
-</head>
-<body>
-<canvas id="gitGraph"></canvas>
-<script src="https://cdnjs.cloudflare.com/ajax/libs/gitgraph.js/1.11.4/gitgraph.min.js" integrity="sha384-2GjLPjUuz0uNoyw8YQ2zQoMBU8q/8opCOxpHOTvMjl1AY6IjI6Lat39y7JhmBpaZ" crossorigin="anonymous"></script>
-<script src="patternlab-flow.js"></script>
-</body>
-</head>
+<html lang="en">
+  <head>
+    <title>Branching scheme</title>
+    <link
+      rel="stylesheet"
+      type="text/css"
+      href="https://cdnjs.cloudflare.com/ajax/libs/gitgraph.js/1.11.4/gitgraph.min.css"
+    />
+    <style>
+      body {
+        margin: 0;
+        padding: 0;
+      }
+    </style>
+  </head>
+  <body>
+    <canvas id="gitGraph"></canvas>
+    <script
+      src="https://cdnjs.cloudflare.com/ajax/libs/gitgraph.js/1.11.4/gitgraph.min.js"
+      integrity="sha384-2GjLPjUuz0uNoyw8YQ2zQoMBU8q/8opCOxpHOTvMjl1AY6IjI6Lat39y7JhmBpaZ"
+      crossorigin="anonymous"
+    ></script>
+    <script src="patternlab-flow.js"></script>
+  </body>
+</html>
