docs(chore): Normalize for consistency (#2206)

"Brief" summary/overview of changes. See the PR discussion or individual commits from the PR for more details.

---

Only applies to the `docs/content/**` content (_and `setup` command_). `target/` and `test/` can be normalized at a later date.

* Normalize to `example.com`

- Domains normalized to `example.com`: `mywebserver.com`, `myserver.tld`, `domain.com`, `domain.tld`, `mydomain.net`, `my-domain.tld`, `my-domain.com`, `example.org`, `whoami.com`.
- Alternative domains normalized to `not-example.com`: `otherdomain.com`, `otherdomain.tld`, `domain2.tld`, `mybackupmx.com`, `whoareyou.org`.
- Email addresses normalized to `admin@example.com` (in `ssl.md`): `foo@bar.com`, `yourcurrentemail@gmail.com`, `email@email.com`, `admin@domain.tld`.
- Email addresses normalized to `external-account@gmail.com`: `bill@gates321boom.com`, `external@gmail.com`, `myemail@gmail.com`, `real-email-address@external-domain.com`.
- **`faq.md`:** A FAQ entry title with `sample.domain.com` changed to `subdomain.example.com`.
- **`mail-fetchmail.md`:** Config examples with FQDNs for `imap`/`pop3` used `example.com` domain for a third-party, changed to `gmail.com` as more familiar third-party/external MTA.

* Normalize config volume path

- Normalizing local config path references to `./docker-data/dms/config/`: `./config/`, `config/`, \``config`\`, `/etc/` (_volume mount src path prefix_).
- Normalize DMS volume paths to `docker-data/dms/mail-{data,state,log}`: `./mail`, `./mail-state` `./data/mail`, `./data/state`, `./data/logs`, `./data/maildata`, `./data/mailstate`, `./data/maillogs`, (_dropped/converted data volumes: `maildata`, `mailstate`_).
- Other docker images also adopt the `docker-data/{service name}/` prefix.

* `ssl.md` - Use `dms/custom-certs` where appropriate.

* Apply normalizations to README and example `docker-compose.yml`

---

Common terms, sometimes interchangeably used or now invalid depending on context: `mail`, `mail container`, `mail server`, `mail-server`, `mailserver`,`docker-mailserver`, `Docker Mailserver`.

Rough transformations applied to most matches (_conditionally, depending on context_):

- 'Docker Mailserver' => '`docker-mailserver`'
- 'mail container' => '`docker-mailserver`' (_optionally retaining ' container'_)
- 'mail server' => 'mail-server' / '`docker-mailserver`'
- 'mail-server' => '`docker-mailserver`'
- 'mailserver' => 'mail-server' / '`docker-mailserver`'

Additionally I checked `docker run` (_plus `exec`, `logs`, etc, sub-commands_) and `docker-compose` commands. Often finding usage of `mail` instead of the expected `mailserver`

Additionally changes `mailserver` hostname in k8s to `mail` to align with other non-k8s examples.

---

* drive-by revisions

Mostly minor revisions or improvements to docs that aren't related to normalization effort.

target/scripts/startup/setup-stack.sh

@@ -293,7 +293,7 @@ function _setup_dovecot_quota
 
       if [[ ! -f /tmp/docker-mailserver/dovecot-quotas.cf ]]
       then
-        _notify 'inf' "'config/docker-mailserver/dovecot-quotas.cf' is not provided. Using default quotas."
+        _notify 'inf' "'/tmp/docker-mailserver/dovecot-quotas.cf' is not provided. Using default quotas."
         : >/tmp/docker-mailserver/dovecot-quotas.cf
       fi
 
@@ -316,7 +316,7 @@ function _setup_dovecot_local_user
     sed -i 's|\r||g' /tmp/docker-mailserver/postfix-accounts.cf
 
     _notify 'inf' "Regenerating postfix user list"
-    echo "# WARNING: this file is auto-generated. Modify config/postfix-accounts.cf to edit user list." > /etc/postfix/vmailbox
+    echo "# WARNING: this file is auto-generated. Modify /tmp/docker-mailserver/postfix-accounts.cf to edit the user list." > /etc/postfix/vmailbox
 
     # checking that /tmp/docker-mailserver/postfix-accounts.cf ends with a newline
     # shellcheck disable=SC1003
@@ -366,7 +366,7 @@ function _setup_dovecot_local_user
       echo "${DOMAIN}" >> /tmp/vhost.tmp
     done < <(grep -v "^\s*$\|^\s*\#" /tmp/docker-mailserver/postfix-accounts.cf)
   else
-    _notify 'inf' "'config/docker-mailserver/postfix-accounts.cf' is not provided. No mail account created."
+    _notify 'inf' "'/tmp/docker-mailserver/postfix-accounts.cf' is not provided. No mail account created."
   fi
 
   if ! grep '@' /tmp/docker-mailserver/postfix-accounts.cf 2>/dev/null | grep -q '|'
@@ -709,7 +709,7 @@ function _setup_postfix_aliases
       [[ ${UNAME} != "${DOMAIN}" ]] && echo "${DOMAIN}" >>/tmp/vhost.tmp
     done < <(grep -v "^\s*$\|^\s*\#" /tmp/docker-mailserver/postfix-virtual.cf || true)
   else
-    _notify 'inf' "Warning 'config/postfix-virtual.cf' is not provided. No mail alias/forward created."
+    _notify 'inf' "Warning '/tmp/docker-mailserver/postfix-virtual.cf' is not provided. No mail alias/forward created."
   fi
 
   if [[ -f /tmp/docker-mailserver/postfix-regexp.cf ]]
@@ -730,7 +730,7 @@ function _setup_postfix_aliases
   then
     cat /tmp/docker-mailserver/postfix-aliases.cf >>/etc/aliases
   else
-    _notify 'inf' "'config/postfix-aliases.cf' is not provided and will be auto created."
+    _notify 'inf' "'/tmp/docker-mailserver/postfix-aliases.cf' is not provided, it will be auto created."
     : >/tmp/docker-mailserver/postfix-aliases.cf
   fi
 
@@ -1264,7 +1264,7 @@ function _setup_postfix_override_configuration
         postconf -e "${LINE}"
       fi
     done < /tmp/docker-mailserver/postfix-main.cf
-    _notify 'inf' "Loaded 'config/postfix-main.cf'"
+    _notify 'inf' "Loaded '/tmp/docker-mailserver/postfix-main.cf'"
   else
     _notify 'inf' "No extra postfix settings loaded because optional '/tmp/docker-mailserver/postfix-main.cf' not provided."
   fi
@@ -1278,7 +1278,7 @@ function _setup_postfix_override_configuration
         postconf -P "${LINE}"
       fi
     done < /tmp/docker-mailserver/postfix-master.cf
-    _notify 'inf' "Loaded 'config/postfix-master.cf'"
+    _notify 'inf' "Loaded '/tmp/docker-mailserver/postfix-master.cf'"
   else
     _notify 'inf' "No extra postfix settings loaded because optional '/tmp/docker-mailserver/postfix-master.cf' not provided."
   fi