LLMService: allow executing tasks sequentially and in parallel

CHANGELOG.md

@@ -11,10 +11,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Function calls can now be executed sequentially (in the order received in the
   completion) by passing `run_in_parallel=False` when creating your LLM
-  service. By default, function calls run in parallel, so if the LLM completion
-  returns 2 or more function calls they run concurrently. In both cases,
-  concurrently and sequentailly, a new LLM completion will run when the last
-  function call finishes.
+  service. By default, if the LLM completion returns 2 or more function calls
+  they run concurrently. In both cases, concurrently and sequentially, a new LLM
+  completion will run when the last function call finishes.
 
 - Added OpenTelemetry tracing for `GeminiMultimodalLiveLLMService` and
   `OpenAIRealtimeBetaLLMService`.