feat: add Home Assistant reverse proxy

conf.d/homeassistant.conf.template

@@ -0,0 +1,12 @@
+server {
+    listen 443 ssl;
+    include snippets/https.conf;
+
+    server_name ha.${BASE_DOMAIN};
+
+    include snippets/proxy.conf;
+
+    location / {
+        proxy_pass http://host.internal:8123;
+    }
+}