Add configuration option to control new window insertion direction

[fcomrqz]

Currently, AeroSpace always inserts new windows at the end (right/bottom) of containers.

It would be great to have an option to control this behavior, for example:

default-insertion-direction = 'left'  # 'left', 'right', 'top', 'bottom'

Current Limitations

• Cannot be achieved through on-window-detected callbacks (limited to move-node-to-workspace and layout commands only)
• Manual repositioning after window creation is the only current workaround

[nikitabobko]

I don't mind to have such configuration option. (Please note that directional approach that you are suggesting doesn't make sense since the orientation is already controlled by default-root-container-orientation)

Converted this discussion to an issue: #1770

If you don't mind, can you please mention your use cases in the issue comments. Is it just a vim habit or there is more to it?