Document caveats

[captbaritone]

1. Only applies to explicitly set "value" attributes. Although this is common in React "controlled components" (proof of concept: https://codesandbox.io/s/1v76x43m5l)
2. Only the first instance of each character would be logged, since the "image" would be cached for the second.

Possibly others?

Great concept though! Thanks for sharing.

Some discussion happening here: https://twitter.com/captbaritone/status/966051583132758016

[StephenLynx]

1: see issue 1, you are correct.
2: only if the server sets a cache, otherwise it would request on every attempt.

[maxchehab]

I updated the README.md pertaining to issue one so I shall close this issue. Thank you for the feedback :)

[treffynnon]

This concept is very similar to something I came across earlier in the year: https://github.com/jbtronics/CrookedStyleSheets

Whilst playing around with it I could not get the browser re-request an image no matter the cache handling server side - the browser was simply uninterested in making an http request to fetch the image more than once. Others have also been halted by this limitation jbtronics/CrookedStyleSheets#6

I tried using pseudo random file names, but CSS won't let you use a concat inside a URI.

Do you have some further detail on how you were able to bust out of the cache?