added robot and sitemap info

README.md

@@ -94,11 +94,17 @@ Re-enable SSH in:
 
 | Path | Purpose |
 |---|---|
+| `/var/lib/gitea/custom/public/` | robots.txt |
+| `/var/lib/gitea/custom/public/` | sitemap.xml |
 | `/var/lib/gitea/custom/public/assets/img/` | Custom images |
 | `/var/lib/gitea/custom/templates/home.tmpl` | Home override |
 | `/etc/gitea/app.ini` | Main config file |
 | `/etc/nginx/conf.d/<domain>.conf` | Vhost generated |
 
+Important (but optional):
+`robots.txt` and `sitemap.xml` are supported automatically by the Nginx configuration being created,
+however the installer does not generate these files. Create them manually in the directory listed above.
+
 ---
 
 ## HTTPS