keybindings.json

// Place your key bindings in this file to override the defaults
[
  {
    "key": "shift+cmd+-",
    "command": "workbench.action.navigateBack",
    "when": "canNavigateBack",
  },
  {
    "key": "ctrl+-",
    "command": "-workbench.action.navigateBack",
    "when": "canNavigateBack",
  },
  {
    "key": "cmd+-",
    "command": "workbench.action.zoomOut",
  },
  {
    "key": "shift+cmd+-",
    "command": "-workbench.action.zoomOut",
  },
  { "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" },
]