Edit user identifier examples: to @alice and @bob

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

roles/custom/matrix-bridge-postmoogle/defaults/main.yml

@@ -100,8 +100,8 @@ matrix_postmoogle_relay_password: ''
 # A list of admins
 # Example set of rules:
 # matrix_postmoogle_admins:
-# - '@someone:example.com'
-# - '@another:example.com'
+# - '@alice:example.com'
+# - '@bob:example.com'
 # - '@bot.*:example.com'
 # - '@*:example.net'
 matrix_postmoogle_admins: "{{ [matrix_admin] if matrix_admin else [] }}"