[Docs] Fix typo ("defult") and double spacing (#34348)

Signed-off-by: SorenDreano <71752785+SorenDreano@users.noreply.github.com>
Co-authored-by: Soren Dreano <soren@numind.ai>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

vllm/config/vllm.py

@@ -278,7 +278,7 @@ class VllmConfig:
     optimization_level: OptimizationLevel = OptimizationLevel.O2
     """The optimization level. These levels trade startup time cost for
     performance, with -O0 having the best startup time and -O3 having the best
-    performance. -02 is used by defult. See  OptimizationLevel for full
+    performance. -O2 is used by default. See OptimizationLevel for full
     description."""
 
     weight_transfer_config: WeightTransferConfig | None = None