Use the same Node version as VSCode

[elenatanasoiu]

As recommended here #1369 (comment), we want to stay in sync with the current node version shipped with VSCode (v16.13.0).

For this we can add a .nvmrc file to alert nvm to switch to the preferred version automatically.

It will also help prevent builds from failing when setting up the project for the first time, as building the extension currently fails in Node v18: #1373

We're also updating the docs to mention using nvm to manage node versions.

Checklist

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.

[aeisenberg]

I think this is generally the right approach, but doing this means we need to be more careful to update the node version requirement when versions in vscode change.

Could you also add a note in the section on releasing in contributing.md to verify the required version of node with the version that vscode uses? And this note should specify all the places that need to be updated when there is a change.

[elenatanasoiu]

@aeisenberg Thanks for the review 💐 I've applied the changes you suggested.

[aeisenberg]

Thanks for the changes. There's one more thing, about updating CONTRIBUTING.md with a new release step. See my comment above.

[elenatanasoiu]

Thanks @aeisenberg, I've added an extra step here.