Swap or remap Cmd+Tab to Ctrl+Tab

Here is the JSON to remap these keys only.

{
  "title": "Cmd+tab maps to Ctrl+tab",
  "rules": [
    {
      "description": "Make Cmd+tab activate Ctrl+tab",
      "manipulators": [
     {
        "type": "basic",
        "from": {
            "key_code": "tab",
            "modifiers": {
                "mandatory": [
                    "command"
                ],
                "optional": [
                    "shift"
                ]
            }
        },
        "to": [
               {
                "key_code": "tab",
                "modifiers": ["control"]
               }
        ]
      }
      ]
    }
  ]
}

If you save the following as a HTML file onto the Desktop and save the t.json above as a t.json file it should let you add as a modification.

<script>
var t = document.location.href.split('/');
t.pop();
t.push('t.json');
t.shift();
t.shift();
t.shift();
var url = 'karabiner://karabiner/assets/complex_modifications/import?url=file%3A%2F%2F%2F'+encodeURIComponent(t.join('/'));


document.write('<a href="'+url+'">Add Modification</a>');

</script>