Fix a typo in quickstart.md (#174)

docs/user/quickstart.md

@@ -30,7 +30,7 @@ most of the model parameters and computation. The server can be started using ei
 for now. To host a server with default experts, run this in your shell:
 
 ```sh
-python scripts/run_server.py --expert_cls ffn --hidden_dim 512 --num_experts 5 --expert_pattern expert.[0:5] \
+python scripts/run_server.py --expert_cls ffn --hidden_dim 512 --num_experts 5 --expert_pattern "expert.[0:5]" \
                              --listen_on 0.0.0.0:1337 --dht_port 1338
 # note: if you omit listen_on and/or dht_port, they will be chosen automatically and printed to stdout.
 ```