Specify minimal supported browser version for min file, README and docs

[renepupil]

Is your feature request related to a problem? Please describe.
I have no idea (any version) min works in e.g. IE10, or another old browser.

Describe the solution you'd like
Specify known minimal browser version in the min file, in the README and in the documentation, obviously this does not apply when used as a JS module or in nodejs as then user will probably use polyfills.

It is also nowhere specified that this should work in all browsers.

Describe alternatives you've considered
At least specify it in the min file.