Added readme file to XamlStyler.Console (fixes #505)

[FroggieFrog]

Description:

Fixes #505

This PR adds a readme file to the NuGet package as suggest by the best practices site.

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have tested my changes by running the extension in VS2017
• I have tested my changes by running the extension in VS2019
• I have tested my changes by running the extension in VS2022
• If changes to the documentation are needed, I have noted this in the description above