friwall: don’t template settings

Let all settings including list of nodes be managed by application.
Exception is the list of networks instantiated from NetBox data.

Also add README.

roles/friwall/tasks/main.yml

@@ -38,17 +38,18 @@
     extra_args: --user --break-system-packages --no-warn-script-location
   notify: restart uwsgi
 
-- name: Configure base settings
-  template:
-    dest: "/srv/friwall/{{ item }}"
-    src: "{{ item }}.j2"
+- name: Ensure setting files exist
+  copy:
+    dest: "/srv/friwall/{{ item }}.json"
+    content: |
+      {}
     owner: friwall
     group: friwall
     mode: 0600
     force: no
   loop:
-    - nodes.json
-    - settings.json
+    - nodes
+    - settings
   notify: restart uwsgi
 
 - name: Configure list of networks