Enable tab switching in VSCode using command + number

gistfile1.txt

Shift command P in VSCode 
> Preferences: Open Keyboard Shortcuts (JSON)
 
 and paste this
 
 
 // Place your key bindings in this file to override the defaults
[
    {
        "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"
    }
]