How to add and format HTML headings, paragraphs, and text in Go?

To add and format HTML headings, paragraphs, and text in Go, you can use the html/template package. Here's an example of how you can create a simple HTML template with headings, paragraphs, and text:

package main

import (
	"html/template"
	"os"
)

type Page struct {
	Title    string
	Headline string
	Content  string
}

func main() {
	page := Page{
		Title:    "My Page",
		Headline: "Welcome to my page!",
		Content:  "This is the content of my page.",
	}

	tmpl, err := template.New("page").Parse(`
		<!DOCTYPE html>
		<html>
		<head>
			<title>{{.Title}}</title>
		</head>
		<body>
			<h1>{{.Headline}}</h1>
			<p>{{.Content}}</p>
		</body>
		</html>
	`)

	if err != nil {
		panic(err)
	}

	err = tmpl.Execute(os.Stdout, page)
	if err != nil {
		panic(err)
	}
}

In the above example, we define a Page struct with Title, Headline, and Content fields. We then create a new template and parse the HTML code, using the {{.FieldName}} syntax to insert values from the Page struct.

Finally, we execute the template by passing in the Page data to tmpl.Execute(), which writes the rendered HTML to os.Stdout. You can also write the output to a file or an HTTP response writer.

This is just a basic example, but you can expand on it and add more complex HTML structures and formatting using the html/template package in Go.