add more random delays

[milahu]

currently there is only

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

Lines 293 to 295 in 2732b5d

	// Navigation is very spotty without this delay; I think it may be due to
	// the screenshot changing the DOM temporarily and not being stable yet.
	await delay(100)

and

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

Line 344 in 2732b5d

await delay(100)

so far i had no problems with these minimal delays
but in a dystopic future, amazon could ban user accounts for scraping

Amazon might ban your account using telemetry for downloading entire books in seconds which is abnormal for typical readers.

You would technically be breaking a digital lock as defined in the DMCA in the USA at least.