Update index.html (#2970)

Changed 'master' to 'main' in order to make the example work correctly.

Author: Dian-Yordanov

src/v2/examples/vue-20-github-commits/index.html

@@ -50,8 +50,8 @@ <h1>Latest Vue.js Commits</h1>
         el: "#demo",
 
         data: {
-          branches: ["master", "dev"],
-          currentBranch: "master",
+          branches: ["main", "dev"],
+          currentBranch: "main",
           commits: null
         },