code: func lexEscapedOpenMustache(l *Lexer) lexFunc {
  	// ignore escape character
  	l.next()
  	l.ignore()
  
  	// scan mustaches
  	for l.peek() == '{' {
  		l.next()
  	}
  
  	return lexContent
  }
docs: // lexEscapedOpenMustache scans \{{