Add unique identifier to docs archetype

[h-enk]

@h-enk In your tutorial here, you need to mention that docs/overview/_index.md also has to be created. Otherwise, the new page does not appear in the docs menu.

Moreover, when I follow this step from the tutorial, the running dev server gives me a warning:

WARN 2022/06/28 23:07:40 "/Users/<...>/Sites/doks/content/en/docs/prologue/introduction.md:1:1": duplicate menu entry with identifier "Introduction" in menu "docs"

Originally posted by @ameotoko in #715 (comment)

[h-enk]

876ad1c

Note that (to be documented), identifier needs to be unique. However (unfortunately), can't use .Parent for this.

Example ./archetypes/docs.md

---
title: "{{ replace .Name "-" " " | title }}"
description: ""
lead: ""
date: {{ .Date }}
lastmod: {{ .Date }}
draft: true
images: []
menu:
  docs:
    parent: ""
    identifier: "{{ .Name }}"
weight: 999
toc: true
---

See also:

• Page variables for Identifier and Name ignored
• Section Variables and Methods

[h-enk]

b468211

For now, made it unique using {{ delimit (shuffle (split (md5 .Name) "" )) "" }},

Resources:

• Generate a Random String in Hugo