npx tsdx create fails when Yarn is not installed

[mikl]

Current Behavior

Running tsdx create without having Yarn installed results in an error like this:

% npx tsdx create edzif-zz
✔ Created edzif-zz
✖ Failed to install dependencies
Error: spawn yarn ENOENT

    at Process.ChildProcess._handle.onexit (internal/child_process.js:240:19)
    at onErrorNT (internal/child_process.js:415:16)
    at process._tickCallback (internal/process/next_tick.js:63:19)

% yarn
zsh: command not found: yarn

Expected behavior

tsdx's documentation could be read like it works with "plain npm", and thus I had expected it to work just having node

Suggested solution(s)

1. If Yarn is required, it should probably be made clear.
2. If not, tsdx create should work without Yarn.

Additional context

N/A

Your environment

Software	Version(s)
TSDX	latest (using npx)
TypeScript	N/A
Browser	N/A
npm/Yarn	6.9.0
Operating System	macOS "Mojave" 14.4.0