Add support for --target

[degrammer]

Is your feature request related to a problem? Please describe.
OpenVSX added support for publishing the extension to specific platforms via --target:
Example:
ovsx ... --target linux-x64

Describe the solution you'd like
Is there any plan to support such an option? Based on my findings is a matter of adding the command here, but I wanted to confirm if this was discussed before or if there is any reason isn't supported.

Describe alternatives you've considered
One alternative is to use ovsx package directly and execute a script from the GitHub Action

Additional context
This was released a while back at eclipse/openvsx#503

[HaaLeo]

Released with v1.5.0. Thx @alexravenna & @degrammer for your contribution.