Document CDP session support

[techulus-agent]

Basecamp To-Do: https://app.basecamp.com/5890597/buckets/40504560/todos/10004635981

Summary:

• Document passing cdp true to create CDP browser sessions.
• Document connectUrl access and incompatibility with proxy and bypassBotDetection.
• Clarify the existing create options docblock with a CDP example.

Verification:

• git diff --check
• PHP/PHPUnit not run locally because php and composer are not installed in this environment.