bug: Running `yo nodecg` in a random empty folder inside of `nodecg` shows error message about package manager

[tobybaratta]

Reproduction steps:

1. Have Node and npm installed, using nvm.
2. Run yo nodecg in an entirely empty folder.
3. Answer prompts normally.
4. See below error message (should maybe be a warning?)

Environment:

• Node version: v18.16.1
• NPM Version: 9.8.0
• Windows 11, run in pwsh preview through Windows Terminal.

Expected behavior

Either:

• detect I am using npm somehow magically
• prompt me and ask what package manager I'm using

Do not fall back to npm without confirming with end-user that that's the desired behavior, IMO, to avoid running into annoying potential symlink issues further down the line.