fix(docs): Not yet Supports files up to 4GB

[cyfung1031]

README claimed that "Supports files up to 4GB", but this is factually incorrect because zip64 support has not yet been implemented - see #230

[101arrowz]

This bullet point refers to GZIP/Zlib/DEFLATE, not ZIP. Pako doesn't support ZIP at all, so this update currently makes it look like fflate has worse support for 4GB files than Pako, while in reality, the level of support is identical. I'd rather remove the bullet point entirely until ZIP64 support is merged, but I do intend to do so for the next release, so this would probably not be gone for too long anyway.

Feel free to switch this to removing the bullet point, otherwise I'll close and the docs will be correct with the next update.

[cyfung1031]

I'd rather remove the bullet point entirely until ZIP64 support is merged

Feel free to switch this to removing the bullet point

OK switched.