publish .vsix file to github release

[aslilac]

Clear and concise description of the problem

Related to #17, it's nice to have installation options that don't require downloading the extension from Microsoft

Suggested solution

There are actions to make this easy like softprops/action-gh-release

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[aslilac]

Thank you for the theme btw 💕 The light version is truly lovely, and has been my theme for probably about a year (which is an eternity for me)