docs: Install with galaxy and use docsmith

Signed-off-by: Julien Riou <julien@riou.xyz>

tasks/deploy-server.yml

@@ -1,4 +1,8 @@
 ---
+- name: check database password
+  ansible.builtin.assert:
+    that: forgejo_db_password is defined
+
 - name: create directories
   ansible.builtin.file:
     state: directory