Update local DB connection string

Author: MackinnonBuck

src/ProjectTemplates/Web.ProjectTemplates/content/BlazorWeb-CSharp/BlazorWebCSharp.1/appsettings.json

@@ -4,7 +4,7 @@
 //#if (UseLocalDB)
 //    "DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=aspnet-BlazorWebCSharp__1-53bc9b9d-9d6a-45d4-8429-2a2761773502;Trusted_Connection=True;MultipleActiveResultSets=true"
 //#else
-//    "DefaultConnection": "DataSource=Data\\app.db;Cache=Shared"
+//    "DefaultConnection": "DataSource=Data/app.db;Cache=Shared"
 //#endif
 //  },
 ////#endif