Suggest text-rendering: geometricPrecision

[JoshData]

Thanks for this great library!

Seems like WebKit and Gecko are too smart and alter textarea text rendering for speed purposes, making it different from div rendering, unless the text-rendering CSS property is set to geometricPrecision.

It might be good to either forcibly set it (though I don't know if that will work) or recommend in the README that it be set by the user in their textarea CSS, e.g.:

textarea { text-rendering: geometricPrecision }

What I experienced was different line spacing between a textarea and the hidden div even though lineHeight was identical.

h/t https://stackoverflow.com/questions/25260908/mismatch-in-text-width-between-div-and-textarea