feat: integration with no-neck-pain

[icristianhernandez]

"No Neck Pain" is a plugin designed to center the current window layout using a split window on each side.

This plugin allows you to specify the desired width of the centered window by adjusting the size of the two side splits. However, when using the "focus" command, the side splits can be unintentionally modified, disrupting the centered layout.

One potential solution could be to implement an "excluded windows" feature. By marking the side splits created by "No Neck Pain" as excluded, the plugin could maintain their size and prevent unintended modifications during focus operations.