After you deploy your site from github, your website root page/directory (yourdomain.azurewebsites.net) may or may not redirect to your site root page ( site main page likes start.html, main.html, home.html) which you used while developing. There are few pages name which are mostly used are predefined in application setting of setting page. It looks like this.
If your website has main page named as one of these page then fortunately your site works well in first shot if not you have to add root/main page name in this list so that azure webapp (website) will redirect to the right page while loading your site. Here I added home.html in list which is my first/main page of site.
Now save this setting and do refresh. BOOM!! Website landed to right page. Thats it!!!