docs: use standard example.com for nginx proxy example

Co-authored-by: gabriel20xx <21219769+gabriel20xx@users.noreply.github.com>

README.md

@@ -506,7 +506,7 @@ DB_PATH=/data/collabtable.db       # SQLite path (in container)
 ```nginx
 server {
     listen 80;
-    server_name yourdomain.com;
+    server_name example.com;
     
     location / {
         proxy_pass http://localhost:3000;