[Archlinux][Vice] Commodore games using vice cannot be launched because of a missing libreadline.so.6

Hello.

I installed Lutris and I added Vice core to play Commodore games. But they did not run. When I looked in a terminal, I got this error:

```
/home/fred/.local/share/lutris/runners/vice/bin/x64: error while loading shared libraries: libreadline.so.6: cannot open shared object file: No such file or directory
```

Temporary fix: installing AUR package readline6.