Serve homepage and static content from root

An alternative (not using ServeMux) solution is to serve explicitly each file located in the root directory. The idea behind is to keep the number of root-based files very small.
sitemap.xml, favicon.ico, robots.txt are indeed mandated to be served out of the root :

package main

import (
    "fmt"
    "net/http"
)

func HomeHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "HomeHandler")
}

func serveSingle(pattern string, filename string) {
    http.HandleFunc(pattern, func(w http.ResponseWriter, r *http.Request) {
        http.ServeFile(w, r, filename)
    })
}

func main() {
    http.HandleFunc("https://stackoverflow.com/", HomeHandler) // homepage

    // Mandatory root-based resources
    serveSingle("/sitemap.xml", "./sitemap.xml")
    serveSingle("/favicon.ico", "./favicon.ico")
    serveSingle("/robots.txt", "./robots.txt")

    // Normal resources
    http.Handle("/static", http.FileServer(http.Dir("./static/")))

    http.ListenAndServe(":8080", nil)
}

Please move all other resources (CSS, JS, etc.) to a proper subdirectory, e.g. /static/ .