feat: add vscode extension to openvsx extension gallery

[faretek1]

This would allow someone to install goboscript from OpenVSX directly in vscodium, because vscodium cannot use the Microsoft marketplace.

See https://github.com/VSCodium/vscodium/blob/master/docs/extensions.md#marketplace

[playforge-coding]

You can just download the extension and then install from the .vsix file.

[faretek1]

You can just download the extension and then install from the .vsix file.

Yes. That was the case before it was on the Microsoft marketplace as well. Why is it on the Microsoft marketplace? Because it's convenient. It hopefully doesn't hurt too much to add it to the open vsix gallery as well