vincentbernat.i3wm-configuration/ws-emacs.json

{
    "layout": "splith",
    "percent": 1,
    "nodes": [
        {"swallows": [{"class": "^Emacs$"}], "percent": 0.5},
        {
            "layout": "splitv",
            "percent": 0.5,
            "nodes": [
                {"swallows": [{"class": "^Vbeterm$"}]},
                {"swallows": [{"class": "^Vbeterm$"}]}
            ]
        }
    ]
}