Chapter 16. a pattern to follow: HTML TemplatesYour web app needs to respond with HTML, not plain text. Plain text is fine for emails and social media posts. But your pages need to be formatted. They need headings and paragraphs. They need forms where your users can submit data to your app. To do any of that, you need HTML code. And eventually, you’ll need to insert data into that HTML code. That’s why Go offers thehtml/template package, a powerful way to include data in your app’s HTML responses. Templates are key to building bigger, better web apps, and in this final chapter, we’ll show you how to use them! A guestbook appLet’s put everything we’ve learned in Chapter 15 to use. We’re going to build a simple guestbook app for a website. Your visitors will be able to enter messages in a form, which will be saved to a file. They’ll also be able to view a list of all the previous signatures. There’s a lot left to cover before we can get this app working, but don’t worry—we’ll be breaking this process down into little steps. Let’s take a look at what will be involved...We’ll need to set up our app and get it to respond to requests for the main guestbook page. This part won’t be too difficult; we’ve already covered everything we need to know in the previous chapter.