footer.tmpl

{{define "footer"}} This is the footer {{end}}

full.tmpl

{{template "header" }} {{block "listOfItems" .}}Hello, this is the list of items. {{end}} {{template "footer"}}

header.tmpl

{{define "header"}} This is the header {{end}}

list_of_items.tmpl

{{define "listOfItems"}} 
    {{range .}} 
        {{println "-" .}}
    {{end}}
{{end}}

usenestedtemplates.go

package main

import (
	"log"
	"os"
	"text/template"
)

func main() {

	var items = []string{"item A", "item B", "item C", "item D", "item E"}

	t, err := template.New("full.tmpl").ParseFiles("full.tmpl", "header.tmpl", "list_of_items.tmpl", "footer.tmpl")
	if err != nil {
		log.Panic(err)
	}
	err = t.Execute(os.Stdout, items)
	if err != nil {
		log.Panic(err)
	}
}