Update the testify.dev landing page to something nicer

[DanielJette]

Is your feature request related to a problem? Please describe.

I like this: https://insert-koin.io/

This feedback relates to:

• The Kotlin library
• The Gradle plugin
• The IntelliJ Platform plugin
• The sample code
• The documentation

Describe the solution you'd like
A clear and concise description of what you want to happen.

Describe alternatives you've considered
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Additional context
Add any other context or screenshots about the feature request here.

[DanielJette]

This is nice https://google.github.io/accompanist/placeholder/

Source: https://github.com/google/accompanist/tree/gh-pages

[DanielJette]

Done