Add blocklist for xiaomi

[ketan]

I'm seeing the following hosts in my pi hole that is used by xiaomi phones to track activity.

It's been blocked by nextdns here here (https://github.com/nextdns/metadata/blob/master/privacy/native/xiaomi). I noticed that the format of this file is not the standard 0.0.0.0 HOSTNAME, so I'm not sure how to get this integrated in the host list directly (short of copying the file over to this repository).

Incidently nextdns has a blocklist with other IoT devices as well (https://github.com/nextdns/metadata/tree/master/privacy/native) that could be integrated here.

Could you let me know how to proceed here, I'm happy to submit a PR if you point me to a previous PR that I can use as a starting point.

[StevenBlack]

Thanks @ketan for this.

I suppose we could make a case for all its sibling folders too.