Update speedcurve.com.json and add a corresponding record in "entities"

[billfitzgerald]

The values in speedcurve.com.json do not currently contain "owner" information. The data below could flesh out the record:

    "owner": {
        "name": "SpeedCurve Limited",
        "displayName": "SpeedCurve",
        "privacyPolicy": "https://www.speedcurve.com/terms/",
        "url": "https://www.speedcurve.com/"
    },

Additionally, I couldn't find a corresponding record for SpeedCurve Limited in the "entities" directory - I'm not sure if this record doesn't exist, or if I'm looking in the wrong place, but I'd be glad to create the json file for it and generate a pull request if that's easier.

I feel relatively confident that I understand (at a high level) the way this dataset is organized, but I also know from painful experience that it's sometimes easier not to deal with pull requests that are almost right, but not quite all the way there.