Update docs/configuring-playbook.md: copy from the MASH project

Copied from 802032cda7/docs/configuring-playbook.md

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

docs/configuring-playbook.md

@@ -24,7 +24,7 @@ If you've configured your DNS records and retrieved the playbook's source code t
 
 2. copy the sample configuration file (`cp examples/vars.yml inventory/host_vars/matrix.example.com/vars.yml`)
 
-3. edit the configuration file (`inventory/host_vars/matrix.example.com/vars.yml`) to your liking. You may also take a look at the various `roles/*/ROLE_NAME_HERE/defaults/main.yml` files and see if there's something you'd like to copy over and override in your `vars.yml` configuration file.
+3. edit the configuration file (`inventory/host_vars/matrix.example.com/vars.yml`) to your liking. You may also take a look at the various `roles/*/ROLE_NAME_HERE/defaults/main.yml` files (after importing external roles with `just update` into `roles/galaxy`) and see if there's something you'd like to copy over and override in your `vars.yml` configuration file.
 
 4. copy the sample inventory hosts file (`cp examples/hosts inventory/hosts`)