WIP: hide columns

[GRbit]

Hi there!

I've made a cool feature which I use a lot, and finally found time to refine the code and make a PR. Now there is a hotkey to hide all the columns but the "Command".

In a small terminal window when I search for commands, it could be just impossible to find the command you need. Look at this: But once I press Ctrl+T, it becomes much clearer:

The only bad thing. It's a bit hard for me to figure out how to write proper tests for it...

It would be very nice to get a couple of hints on how to do this, or at least to know if the feature looks good to you and you want to have. Knowing that I'm not the only one who wants it would give me some motivation.