CSS Transform: Replace link text and source

[c8in4]

Because

The previous resource in the second Assignment included several inaccuracies that led to confusion.

This PR

• change text label from [the perspective property on CSS tricks] to [perspective in CSS]
• replace link with: (https://3dtransforms.desandro.com/perspective)

Issue

Closes #28708

Additional Information

Discord conversation on the contradicting info for transform order

Lesson Url

https://www.theodinproject.com/lessons/node-path-advanced-html-and-css-transforms#assignment

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[MaoShizhong]

Congrats on your first PR here 🚀

[c8in4]

Thank you, @MaoShizhong,
That was exciting! 😅