[Docs] Add a document describing Jax dynamically-shaped arrays

[sergei-mironov]

Context: This PR adds a document describing the Jax dynamic API and the Catalyst-specific extensions to it.

Description of the Change:

Benefits:

Possible Drawbacks:

Related GitHub Issues:

• https://github.com/PennyLaneAI/catalyst/pull/775
• https://github.com/PennyLaneAI/catalyst/pull/777
• https://github.com/PennyLaneAI/catalyst/pull/830

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