Add new-tab-neighbor option to detach_window

[ces42]

This should be pretty self-explanatory.

Rationale: I usually have plenty of different tabs open in which I'm doing different things (work/system troubleshooting/configuring nvim/htop/...) and use detach_window when my current tab gets too crowded. I would like related tabs to stay together, so an option to detach a window to a new tab, which gets created next to the current tab would be useful.

[kovidgoyal]

Not sure I follow wont tab-right or tab-left do what you want already?

[ces42]

Uh, it seems to me tab-right and tab-left don't create new tabs (i.e. they move the window more than detaching it). I just want new-tab except the new tab is created next to the active tab.

[kovidgoyal]

ah ok you want a new empty tab. Maybe have new-tab-left and
new-tab-right then. Am sure someone in the future will want to detach to
a tab to the left instead of neighbor which IIRC is the tab to the
right.

[ces42]

Yes probably new-tab-left is also useful. Do you want me to implement it?

[kovidgoyal]

yes.