Support package.json repository.directory field

[Philipp15b]

When guessing the baseUrls (see guessBaseUrls function), vscode-vsce does not seem to respect the optional directory field in the package.json. It allows specifying a subdirectory in which the extension lives. I expected that the base urls are guessed with respect to that directory. Thanks!

[junqi-lu]

I have encountered the same issue. It would be great if this feature could be supported.