feat: initial Nginx templates

conf.d/gitea.conf.template

@@ -0,0 +1,13 @@
+server {
+    listen 443 ssl;
+    include snippets/https.conf;
+
+    server_name gitea.${BASE_DOMAIN};
+
+    include snippets/proxy.conf;
+
+    location / {
+        proxy_pass http://gitea:3000;
+        client_max_body_size 512M;
+    }
+}