Recommend specifying dependencies for linux version of the engine

[SugarRayLua]

Hi, AbyssEngine team. I think it is great you are working on an OpenDiablo2 project. DevilutionX is amazing for Diablo I and would be neat if can achieve the same success for Diablo 2. I'm using Linux and downloaded the project to check it out but found out the AbyssEngine would not work as it apparently depends on glibc >=2.29, and I'm limited to 2.28 with Debian 10. Happy to check the project out again when I upgrade but thought it might be helpful if you post linux dependencies on the GitHub site for others wanting to help out or test out. Thanks.