Requires zlib on Debian/Ubuntu

[sir4ur0n]

This library needs zlib to be installed, but it's not mentioned in the Debian prerequisites.

On a freshly installed Ubuntu 20.04 (WSL) I had to install the zlib1g-dev package (not zlib1g) before the Haskell zlib package would compile.

[jneira]

Thanks for noting it, would you be interested in open a pr to correct install instructions?

[sir4ur0n]

Yes sorry, should have mentioned, I'm already working on it (running tests for older Ubuntu version 18.04), PR should land shortly after