Add hard-coded breadcrumbs to documentation files about installation procedure for easier navigation

Since it is easy to get lost among these files, the breadcrumbs should be helpful to get the whole picture of the procedure. Hopefully they will be replaced with something else generated automatically.

Please note that the usage of <sup> HTML tags on this context is not proper as the tag is intended to be used only for typographical reasons. Here <small> tags should rather be used instead as long as we do not use CSS, but since GitHub strips these tags against its spec (https://github.github.com/gfm/#disallowed-raw-html-extension-) (also note: the <small> HTML tags are not stripped on Codeberg for example), this commit intentionally uses <sup> to have those breadcrumbs rendered in small points.

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-dns.md

@@ -1,5 +1,7 @@
 # Configuring your DNS server
 
+<sup>[Prerequisites](prerequisites.md) > Configuring your DNS server > [Getting the playbook](getting-the-playbook.md) > [Configuring the playbook](configuring-playbook.md) > [Installing](installing.md) </sup>
+
 To set up Matrix on your domain, you'd need to do some DNS configuration.
 
 To use an identifier like `@<username>:example.com`, you don't actually need to install anything on the actual `example.com` server.

docs/configuring-playbook.md

@@ -1,5 +1,7 @@
 # Configuring the Ansible playbook
 
+<sup>[Prerequisites](prerequisites.md) > [Configuring your DNS server](configuring-dns.md) > [Getting the playbook](getting-the-playbook.md) > Configuring the playbook > [Installing](installing.md) </sup>
+
 To configure the playbook, you need to have done the following things:
 
 - have a server where Matrix services will run

docs/getting-the-playbook.md

@@ -1,5 +1,7 @@
 # Getting the playbook
 
+<sup>[Prerequisites](prerequisites.md) > [Configuring your DNS server](configuring-dns.md) > Getting the playbook > [Configuring the playbook](configuring-playbook.md) > [Installing](installing.md) </sup>
+
 This Ansible playbook is meant to be executed on your own computer (not the Matrix server).
 
 In special cases (if your computer cannot run Ansible, etc.) you may put the playbook on the server as well.

docs/installing.md

@@ -1,5 +1,7 @@
 # Installing
 
+<sup>[Prerequisites](prerequisites.md) > [Configuring your DNS server](configuring-dns.md) > [Getting the playbook](getting-the-playbook.md) > [Configuring the playbook](configuring-playbook.md) > Installing </sup>
+
 If you've [configured your DNS](configuring-dns.md) and have [configured the playbook](configuring-playbook.md), you can start the installation procedure.
 
 **Before installing** and each time you update the playbook in the future, you will need to update the Ansible roles in this playbook by running `just roles`. `just roles` is a shortcut (a `roles` target defined in [`justfile`](../justfile) and executed by the [`just`](https://github.com/casey/just) utility) which ultimately runs [agru](https://github.com/etkecc/agru) or [ansible-galaxy](https://docs.ansible.com/ansible/latest/cli/ansible-galaxy.html) (depending on what is available in your system) to download Ansible roles. If you don't have `just`, you can also manually run the `roles` commands seen in the `justfile`.

docs/prerequisites.md

@@ -1,5 +1,7 @@
 # Prerequisites
 
+<sup>Prerequisites > [Configuring your DNS server](configuring-dns.md) > [Getting the playbook](getting-the-playbook.md) > [Configuring the playbook](configuring-playbook.md) > [Installing](installing.md) </sup>
+
 To install Matrix services using this Ansible playbook, you need:
 
 - (Recommended) An **x86** server ([What kind of server specs do I need?](faq.md#what-kind-of-server-specs-do-i-need)) running one of these operating systems that make use of [systemd](https://systemd.io/):