Add "add" saving mode

[eater]

Because scratchpad windows are not a fixed workspace, but rather used like a palette or library of windows that can be displayed one or several at a time, it would be useful to be able to add elements to a resurrectable list of scratchpad windows, rather than rebuild the entire list on each save.

So I propose a command flag like i3-resurrect save -w __i3_scratch --add that would keep the current contents of the saved (scratch) workspace, but add to it any additional unique windows that are open on that workspace.

[JonnyHaystack]

Just so you know, I am considering this but it may be a while before it happens as it would add quite a lot of complexity.

[eater]

Quite possibly not worth it then, unless adding that complexity could add additional value beyond my little whim here.