Only runs on Mac: one line change to playwright required

[barakplasma]

The following line causes this program to fail on Linux, or Windows:

kindle-ai-export/src/extract-kindle-book.ts

Lines 50 to 51 in 2732b5d

	executablePath:
	'/Applications/Google Chrome.app/Contents/MacOS/Google Chrome',

It can be safely removed for most people after running npx playwright install --with-deps chrome`