Add temporary nodeJS walkthrough

[bhavyaus]

Fixes: #181400
This is a temp fix.

Commit 9302611 removes a walkthrough from a builtin extension.
The place where we are stuck

vscode/src/vs/workbench/contrib/welcomeGettingStarted/browser/gettingStarted.ts

Line 887 in 6812cf9

await this.gettingStartedService.installedExtensionsRegistered;

is waiting on a promise that only resolves when an extension’s contributed walkthroughs are processed, and with that commit, we no longer have any builtin extensions contributing a walkthrough.

Temporary fix is to add in a placeholder walkthrough that is disabled with a when clause and that gets everything working the way it did before.

PR in main: #181441

[Salome085]

✅