docs: Fix formatting of UTM parameters example in assets.rst

[adi-ray]

Linked issue

Closes #502

[adiati98]

Hey @adi-ray,

I see that you haven't been assigned to the issue. Can you please comment on the issue so we can assign it to you?

As this is a small fix, we let you grab sub-issues for all branches, including #503. So please comment on that as well.

However, for the next, kindly ask for an issue and ensure that it's assigned to you before you work on it. An issue that hasn't been assigned is considered free for others to work on. That said, if anyone ask to be assigned to a vacant issue, we'll assign it to them.

Thank you.

[adiati98]

Thanks for the PR, @adi-ray!

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