func HelpPrinter(w io.Writer, templ string, data interface{}) {
	b := helpPreprocessor(w, templ, data, false)
	w.Write(Render(b))
}
HelpPrinter overwrites cli.HelpPrinter and prints the formatted help to the terminal.
package usage
import (
	"bytes"
	"fmt"
	"io"
	"regexp"
	"strings"
	"text/template"
	"unicode"
	md "github.com/smallstep/cli/pkg/blackfriday"
	"github.com/urfave/cli"
)
var sectionRe = regexp.MustCompile(`(?m:^##)`)
var sectionNameRe = regexp.MustCompile(`(?m:^## [^\n]+)`)
var indentRe = regexp.MustCompile(`(?m:^:[^\n]+)`)
var definitionListRe = regexp.MustCompile(`(?m:^[\t ]+\*\*[^\*]+\*\*[^\n]*\s+:[^\n]+)`)
type frontmatterData struct {
	Data     interface{}
	Parent   string
	Children []string
}