Add Categories and Repository properties to results from Get-VSCodeExtension

[AjayKMehta]

This module is already very useful but it would be even more amazing if Categories and Repository properties were added to the results returned from Get-VSCodeExtension 😀

Code is very simple and would be happy to submit a PR for this.

# Add to line 39 of Get-VSCodeExtension.ps1
'Categories'    = $PackageJson.Categories
'Repository'    = $PackageJson.Repository.Url

Thanks.