Add Fluent Bit sandbox button to homepage

[Anurag Gupta]

Next to the Download Now, we should have Try Now that points to the following embedded URL

<iframe width="1140" height="640" sandbox="allow-same-origin allow-scripts allow-popups allow-forms allow-modals" src="https://play.instruqt.com/embed/Fluent/tracks/fluent-bit-getting-started-101?token=em_S2zOzhhDQepM0vDS" style="border: 0;"></iframe>