docs(docstrings): remove "Skins" in Extension docstring

[Catalyst4222]

Pull Request Type

• Feature addition
• Bugfix
• Documentation update
• Code refactor
• Tests improvement
• CI/CD pipeline enhancement
• Other: [Replace with a description]

Description

Changed the word "Skins" in the Extension docstring to "Extensions"

Changes

Changed the word "Skins" in the Extension docstring to "Extensions"

Related Issues

N/A

Test Scenarios

N/A

Python Compatibility

• I've ensured my code works on Python 3.10.x
• I've ensured my code works on Python 3.11.x

Checklist

• I've run the pre-commit code linter over all edited files
• I've tested my changes on supported Python versions
• I've added tests for my code, if applicable
• I've updated / added documentation, where applicable

[AstreaTSS]

Wow, this is from years ago. Just shows how stable some of this code is 😅.