monica: add docker compose-based config

roles/monica-web/meta/main.yml

@@ -0,0 +1,3 @@
+---
+dependencies:
+  - role: caddy

roles/monica-web/tasks/main.yml

@@ -0,0 +1,9 @@
+---
+- name: Ensure Caddyfile is present
+  template:
+    src: 'monica.Caddyfile.j2'
+    dest: '/etc/caddy/monica.Caddyfile'
+    owner: root
+    group: root
+    mode: '0644'
+  notify: caddy-reload

roles/monica-web/templates/monica.Caddyfile.j2

@@ -0,0 +1,3 @@
+prm.roosens.me {
+    reverse_proxy {{ groups['monica'][0] }}:8001
+}