Publish to Open-VSX

[encode42]

Is your feature request related to a problem? Please describe.
I use a distribution of Visual Studio Code that doesn't include Microsoft's telemetry. Because of this, VSCodium utilizes Open-VSX as their marketplace.

Describe the solution you'd like
Publish to Open-VSX alongside the VSCode marketplace.

Additional context
I read somewhere the instructions on how to do this. It should be a very easy change (one additional line to the publishing script) that has no compromises.

[encode42]

Closed because I realized this isn't for the VSCode extension 🤦‍♂️