[prh8]

I map it to Hyper, but you can tweak this to just be control:

    {
        "description": "Change caps_lock to hyper/escape.",
        "from": {
            "key_code": "caps_lock",
            "modifiers": {
                "optional": [
                    "any"
                ]
            }
        },
        "to": [
            {
                "key_code": "left_shift",
                "modifiers": [
                    "left_command",
                    "left_control",
                    "left_option"
                ]
            }
        ],
        "to_if_alone": [
            {
                "key_code": "escape"
            }
        ],
        "type": "basic"
    }