Fix minor typo in ASP.NET Core tutorials (#1293)

* Fix minor typo in tutorials/aspnetcore.md

* Fix typo in reactnet-vanilla/Startup.cs

Author: Bonfire

site/jekyll/tutorials/aspnetcore.md

@@ -149,7 +149,7 @@ app.UseReact(config =>
   //  .AddScript("~/js/First.jsx")
   //  .AddScript("~/js/Second.jsx");
 
-  // If you use an external build too (for example, Babel, Webpack,
+  // If you use an external build tool (for example, Babel, Webpack,
   // Browserify or Gulp), you can improve performance by disabling
   // ReactJS.NET's version of Babel and loading the pre-transpiled
   // scripts. Example:

src/React.Template/reactnet-vanilla/Startup.cs

@@ -72,7 +72,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerF
 						ContractResolver = new CamelCasePropertyNamesContractResolver()
 					});
 
-				// If you use an external build too (for example, Babel, Webpack,
+				// If you use an external build tool (for example, Babel, Webpack,
 				// Browserify or Gulp), you can improve performance by disabling
 				// ReactJS.NET's version of Babel and loading the pre-transpiled
 				// scripts. Example: