Add U+25B6 (BLACK RIGHT-POINTING TRIANGLE) characters to installation procedure navigation

Set anchor links to those characters as well.

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

docs/configuring-dns.md

@@ -105,4 +105,4 @@ To make the [postmoogle](configuring-playbook-bridge-postmoogle.md) email bridge
 
 ---------------------------------------------
 
-When you're done with the DNS configuration and ready to proceed, continue with [Getting the playbook](getting-the-playbook.md).
+[▶️](getting-the-playbook.md) When you're done with the DNS configuration and ready to proceed, continue with [Getting the playbook](getting-the-playbook.md).

docs/configuring-playbook.md

@@ -28,7 +28,7 @@ For a basic Matrix installation, that's all you need.
 
 For a more custom setup, see the [Other configuration options](#other-configuration-options) below.
 
-When you're done with all the configuration you'd like to do, continue with [Installing](installing.md).
+[▶️](installing.md) When you're done with all the configuration you'd like to do, continue with [Installing](installing.md).
 
 
 ## Other configuration options

docs/getting-the-playbook.md

@@ -37,4 +37,4 @@ You can extract this archive anywhere. You'll get a directory called `matrix-doc
 
 ---------------------------------------------
 
-No matter which method you've used to download the playbook, you can proceed by [Configuring the playbook](configuring-playbook.md).
+[▶️](configuring-playbook.md) No matter which method you've used to download the playbook, you can proceed by [Configuring the playbook](configuring-playbook.md).

docs/prerequisites.md

@@ -48,4 +48,4 @@ To install Matrix services using this Ansible playbook, you need:
 
 ---------------------------------------------
 
-When ready to proceed, continue with [Configuring DNS](configuring-dns.md).
+[▶️](configuring-dns.md) When ready to proceed, continue with [Configuring DNS](configuring-dns.md).