Replaced link to Jupyter environment in README

[Darylgolden]

Changelog / Overview

Motivation

The README links to an old binder notebook running Manim 0.3.0. I replaced it with a link to https://try.manim.community/.

Explanation for Changes

Documentation Reference

Testing Status

Further Comments

Checklist

• I have read the Contributing Guidelines
• I have written a descriptive PR title (see top of PR template for examples)
• I have written a changelog entry for the PR or deem it unnecessary
• My new functions/classes either have a docstring or are private
• My new functions/classes have tests added and (optional) examples in the docs
• My new documentation builds, looks correctly formatted, and adds no additional build warnings

Reviewer Checklist

• The PR title is descriptive enough
• The PR is labeled correctly
• The changelog entry is completed if necessary
• Newly added functions/classes either have a docstring or are private
• Newly added functions/classes have tests added and (optional) examples in the docs
• Newly added documentation builds, looks correctly formatted, and adds no additional build warnings