docs(index): fix missing comma (#230)

Author: dkundel-openai

docs/src/content/docs/index.mdx

@@ -21,7 +21,7 @@ The [OpenAI Agents SDK for TypeScript](https://github.com/openai/openai-agents-j
 enables you to build agentic AI apps in a lightweight, easy-to-use package with
 very few abstractions. It's a production-ready upgrade of our previous
 experimentation for agents,
-[Swarm](https://github.com/openai/swarm/tree/main) that's also [available in Python](https://github.com/openai/openai-agents-python). The Agents SDK has a very
+[Swarm](https://github.com/openai/swarm/tree/main), that's also [available in Python](https://github.com/openai/openai-agents-python). The Agents SDK has a very
 small set of primitives:
 
 - **Agents**, which are LLMs equipped with instructions and tools