Add a new layout Columns

[jecaro]

Description

This layout organizes windows in columns and allows to move/resize them in every direction. This layout is showcased here: https://jeancharles.quillet.org/posts/2024-05-02-Columns-a-new-XMonad-layout.html

I was reluctant to send this layout in a PR because I'm not sure I'd have time to maintain it outside my main configuration. But I've been told that some people might be volunteers to maintain it 🙂 So here it is.

Something that might be annoying is that the parameter to toggle between wide screen and small screen is currently hardcoded. As the layout lives in my config, this is not a problem for me but it might be for others. I can make it configurable if needed tho.

Checklist

• I've read CONTRIBUTING.md

• I've considered how to best test these changes (property, unit, manually, ...) and concluded: I've been using this layout for more than one year now. It works fine for my usage. It has a few annoyances sometimes when using a tabbed sublayout but despite that it works great.

• I updated the CHANGES.md file

[geekosaur]

I'm sorry for the delay; my network's been out for two weeks.