Update Kubermatic Logo on Landing page

[KrissiWi]

Hi there,

We do have a new logo that would need to be changed on your website.

(If there is a way I can do it myself please letme know. I just could not find it at first sight)

Thanks,

Krissi

[brian-brazil]

It's at https://github.com/prometheus/docs/tree/master/static/company-logos if you'd like to send a PR.

[dcierco]

The logo has already been updated in this PR.