added changes

Author: saminacodes

apps/portal/src/app/nebula/plugins/openAI/page.mdx

@@ -1,11 +1,12 @@
-**Chat Completions API**
+# Chat Completions API
+
 Compatible with OpenAI’s Chat Completion API to process chat history and generate context-aware responses.
 
 ```python
 from openai import OpenAI
 
 client = OpenAI(
-	base_url="<https://nebula-api.thirdweb.com/>",
+	base_url="https://nebula-api.thirdweb.com",
 	api_key="{{THIRDWEB_SECRET_KEY}}",
 )