Documentation for Fullscreen extension methods is wrong

[DanielJette]

Describe the bug A clear and concise description of what the bug is.

This issue relates to:

• [ ] The Kotlin library
• [ ] The Gradle plugin
• [ ] The IntelliJ Platform plugin
• [ ] The sample code
• [ ] The documentation
• [x] The Fullscreen extension

To Reproduce

Documentation refers to the ScreenshotRule extension methods, but these were relocated to the TestifyConfiguration