docs(refactor): Large refactor + additions + fixes

Consistency pass, formatting cleanup and fixes, introduce admonitions, add front-matter.

---

docs: Add front-matter

---

docs: Fix and format links

- Some links were invalid (eg files moved or renamed)
- Some were valid but had invalid section headers (content removed or migrated)
- Some use `http://` instead of `https://` when the website supports a secure connection.
- Some already used the `[name][reference]` convention but often with a number that wasn't as useful for maintenance.
- All referenced docs needed URLs replaced. Opted for the `[name][reference]` approach to group them all clearly at the bottom of the doc, especially with the relative URLs and in some cases many duplicate entries.
- All `tomav` references from the original repo prior to switch to an organization have been corrected.
- Minor cosmetic changes to the `name` part of the URL, such as for referencing issues to be consistent.
- Some small changes to text body, usually due to duplicate URL reference that was unnecessary (open relay, youtous)
- Switched other links to use the `[name][reference]` format when there was a large group of URLs such as wikipedia or kubernetes. Github repos that reference projects related to `docker-mailserver` also got placed here so they're noticed better by maintainers. This also helped quite a bit with `mermaid` external links that are very long.
- There was a Github Wiki supported syntax in use `[[name | link]]` for `fetchmail` page that isn't compatible by default with MkDocs (needs a plugin), converted to `[name][reference]` instead since it's a relative link.

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docs: Update commit link for LDAP override script

Logic moved to another file, keeping the permalink commit reference so it's unaffected by any changes in the file referenced in future.

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docs: Heading corrections

Consistency pass. Helps with the Table of Contents (top-right UI) aka Document Outline.
docs: codefence cleanup

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docs: misc cleanup

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docs: Add Admonitions

Switches `<details>` usage for collapsible admonitions (`???`) while other text content is switched to the visually more distinct admoniton (`!!!` or `???+`) style.

This does affect editor syntax highlighting a bit and markdown linting as it's custom non-standard markdown syntax.

docs/content/advanced/auth-ldap.md

@@ -1,4 +1,8 @@
-### Introduction
+---
+title: 'LDAP Authentication'
+---
+
+## Introduction
 
 Getting started with ldap and this mailserver we need to take 3 parts in account:
 
@@ -6,9 +10,10 @@ Getting started with ldap and this mailserver we need to take 3 parts in account
 * DOVECOT
 * SASLAUTHD (this can also be handled by dovecot above)
 
-### List with the variables to control the container provisioning
+## Variables to Control Provisioning by the Container
 
 __POSTFIX__:
+
 * `LDAP_QUERY_FILTER_USER`
 * `LDAP_QUERY_FILTER_GROUP`
 * `LDAP_QUERY_FILTER_ALIAS`
@@ -19,14 +24,16 @@ __SASLAUTHD__:
 * `SASLAUTHD_LDAP_FILTER`
 
 __DOVECOT__:
+
 * `DOVECOT_USER_FILTER`
 * `DOVECOT_PASS_FILTER`
 
+!!! note
+    This page will provide several use cases like recipes to show, how this project can be used with it's LDAP Features.
 
-**NOTE**: This page will provide several use cases like recipes to show, how this project can be used with it's LDAP Features.
+## LDAP Setup - Kopano / Zarafa
 
-### Ldap Setup - Kopano/Zarafa
-```yml
+```yaml
 ---
 version: '2'
 
@@ -55,7 +62,7 @@ services:
       - ENABLE_CLAMAV=1
       - ENABLE_FAIL2BAN=1
       - ENABLE_POSTGREY=1
-      - SASLAUTHD_PASSWD=      
+      - SASLAUTHD_PASSWD=
 
       # >>> SASL Authentication
       - ENABLE_SASLAUTHD=1
@@ -100,19 +107,18 @@ volumes:
     driver: local
 ```
 
-If your directory has not the postfix-book schema installed, then you must change the internal attribute handling for dovecot. For this you have to change the ```pass_attr``` and the ```user_attr``` mapping, as shown in the example below: 
+If your directory has not the postfix-book schema installed, then you must change the internal attribute handling for dovecot. For this you have to change the `pass_attr` and the `user_attr` mapping, as shown in the example below:
 
-```yml
-    - DOVECOT_PASS_ATTR=<YOUR_USER_IDENTIFYER_ATTRIBUTE>=user,<YOUR_USER_PASSWORD_ATTRIBUTE>=password
-    - DOVECOT_USER_ATTR=<YOUR_USER_HOME_DIRECTORY_ATTRIBUTE>=home,<YOUR_USER_MAILSTORE_ATTRIBUTE>=mail,<YOUR_USER_MAIL_UID_ATTRIBUTE>=uid, <YOUR_USER_MAIL_GID_ATTRIBUTE>=gid
+```yaml
+- DOVECOT_PASS_ATTR=<YOUR_USER_IDENTIFYER_ATTRIBUTE>=user,<YOUR_USER_PASSWORD_ATTRIBUTE>=password
+- DOVECOT_USER_ATTR=<YOUR_USER_HOME_DIRECTORY_ATTRIBUTE>=home,<YOUR_USER_MAILSTORE_ATTRIBUTE>=mail,<YOUR_USER_MAIL_UID_ATTRIBUTE>=uid, <YOUR_USER_MAIL_GID_ATTRIBUTE>=gid
 ```
 
-The following example illustrates this for a directory that has the qmail-schema installed and that uses ```uid```:
+The following example illustrates this for a directory that has the qmail-schema installed and that uses `uid`:
 
-```yml
-      - DOVECOT_PASS_ATTRS=uid=user,userPassword=password
-      - DOVECOT_USER_ATTRS=homeDirectory=home,qmailUID=uid,qmailGID=gid,mailMessageStore=mail
-      - DOVECOT_PASS_FILTER=(&(objectClass=qmailUser)(uid=%u)(accountStatus=active))
-      - DOVECOT_USER_FILTER=(&(objectClass=qmailUser)(uid=%u)(accountStatus=active))
+```yaml
+- DOVECOT_PASS_ATTRS=uid=user,userPassword=password
+- DOVECOT_USER_ATTRS=homeDirectory=home,qmailUID=uid,qmailGID=gid,mailMessageStore=mail
+- DOVECOT_PASS_FILTER=(&(objectClass=qmailUser)(uid=%u)(accountStatus=active))
+- DOVECOT_USER_FILTER=(&(objectClass=qmailUser)(uid=%u)(accountStatus=active))
 ```
-