When using icat with tmux we get the following:
```
$ kitty icat ~/Pictures/fc.jpg
Terminal does not support reporting screen sizes via the TIOCGWINSZ ioctl
```
I found a suggestion[1] this is due to limitations between kitty and tmux, so I'm raising this PR to either confirm this is the case and make it clear in the documentation, or to have it rejected so an issue can be raised to address the feature.
1: https://unix.stackexchange.com/a/484776/41996
