Proposal for Fixed Window Sizes

[fg123]

It would a good feature to allow a single window to be fixed a certain size, while the other ones are flex.

The proposal I think that makes sense is to only allow windows along the border to be of a fixed size. A window can be fixed in two directions, either horizontally or vertically (or both). For a window to be able to be fixed horizontally, it must have one edge touching either the left or the right. Same for vertically.

When a window is fixed, it's size is as such, and the windows around it flex around it at the same proportion as defined by their size numbers (which are percentages). There's going to be some challenges in arranging the DOM to accommodate these fixed windows but this is the general high level idea.