(Fix #689): change the cursor from arrow to pointer in send button.

[subhamkumarr]

Fixes: change the cursor from arrow to pointer in the send button.

Screenshots:

Before:

https://github.com/CircuitVerse/Interactive-Book/assets/99977240/8885a01a-8792-47ba-a228-62ebd98fec70

After:

https://github.com/CircuitVerse/Interactive-Book/assets/99977240/2d5a6add-8c4e-4d95-a982-d5ea60a68c38

Preview Link(s): https://github.com/CircuitVerse/Interactive-Book/issues/689

✅️ By submitting this PR, I have verified the following

• [X] Checked to see if a similar PR has already been opened 🤔️
• [X] Reviewed the contributing guidelines 🔍️
• [X] Sample preview link added (add the link(s) for all the pages changed/updated from the checks tab after checks complete)
• [X] Tried Squashing the commits into one

[subhamkumarr]

@tanmoysrt @tachyons Could you please review this?

[subhamkumarr]

Hey maintainers could you please review this PR.