Yarn PnP support

[AnhNhan]

Hello,

currently this package makes fixed assumptions about the node_modules folder, which is not a given when using Yarn 2 in Plug-and-Play mode.

It would be better to use require.resolve(), e.g.

// this here
const npm3Path = path.resolve(__dirname, '..', target);

// becomes this
const npm3Path = require.resolve('@ffprobe-installer/' + target + '/' + binary)

// example
require.resolve('@ffprobe-installer/win32-x64/ffprobe.exe')

// returns
const result = 'C:\\Users\\user\\dev\\project\\.yarn\\unplugged\\@ffprobe-installer-win32-x64-npm-5.0.0-6664c83f60\\node_modules\\@ffprobe-installer\\win32-x64\\ffprobe.exe';

[milkcoke]

I'm also waiting this issue is resolved.

[SavageCore]

I myself don't use Yarn PnP but happy to receive a full PR also covering npm2Path (if needed)