In the Solution Explorer, right click on the project and go to "Properties". In the "Build" tab check the "XML documentation file" checkbox.
Then copy the generated XML file from the bin folder into the project, commonly "App_Data" folder. Reference the file in the HelpPageConfig.cs
of the Help Page MVC area. There will be a commented out line that looks something like config.SetDocumentationProvider(new XmlDocumentationProvider(
HttpContext.Current.Server.MapPath("~/App_Data/Doc.xml")));
Change the XML file name and uncomment the line.