Update the vs-code extension

[Cyberbeni]

There is an open pull request there: stencilproject/vscode-stencil#2 (comment)

[vknabel]

I'd be happy to (co-)maintain the vscode-extension in the long term if you need help with it. But this requires someone who can actually publish updates to the VS Code Marketplace.

If you need help with this main repository, I can only offer responding to issues, closing stale ones, labelling them and eventually code-reviewing some PRs. Bumping Swift / Toolchain should be fine, too.
I probably wouldn't be able to actually test bigger PRs, fixing bugs or implementing new features.