{
    "profiles": [
        {
            "name": "Default profile",
            "selected": true,
            "simple_modifications": {
                "non_us_backslash": "grave_accent_and_tilde"
            }
        }
    ]
}

Add example to change Section key § with ` and plus minus ± with tilde ~
Add example to change Section key § with ` and plus minus ± with tilde ~

To help users like 

https://github.com/tekezo/Karabiner-Elements/issues/30
https://github.com/tekezo/Karabiner-Elements/issues/7