keybindings.json

// Place your key bindings in this file to overwrite the defaults
[
  {
    "key": "cmd+0",
    "command": "workbench.action.openLastEditorInGroup"
  },
  {
    "key": "cmd+1",
    "command": "workbench.action.openEditorAtIndex1"
  },
  {
    "key": "cmd+2",
    "command": "workbench.action.openEditorAtIndex2"
  },
  {
    "key": "cmd+3",
    "command": "workbench.action.openEditorAtIndex3"
  },
  {
    "key": "cmd+4",
    "command": "workbench.action.openEditorAtIndex4"
  },
  {
    "key": "cmd+5",
    "command": "workbench.action.openEditorAtIndex5"
  },
  {
    "key": "cmd+6",
    "command": "workbench.action.openEditorAtIndex6"
  },
  {
    "key": "cmd+7",
    "command": "workbench.action.openEditorAtIndex7"
  },
  {
    "key": "cmd+8",
    "command": "workbench.action.openEditorAtIndex8"
  },
  {
    "key": "cmd+9",
    "command": "workbench.action.openEditorAtIndex9"
  },
  {
    "key": "ctrl+1",
    "command": "workbench.action.focusFirstEditorGroup"
  },
  {
    "key": "ctrl+2",
    "command": "workbench.action.focusSecondEditorGroup"
  },
  {
    "key": "ctrl+3",
    "command": "workbench.action.focusThirdEditorGroup"
  }
]