Replace the official logo for Jenkins Docker packaging

[oleg-nenashev]

Follow-up to https://github.com/jenkins-infra/jenkins.io/pull/3181#issuecomment-626667853 .

As @sudo-bmitch mentioned in Twitter, our Docker packaging logo needs updating: https://twitter.com/sudo_bmitch/status/1258374592202244097 . Official guidelines from Docker: https://www.docker.com/company/newsroom/media-resources

Scope of the changes:

• Logos in the jenkins.io resources, especially the logo itself and opengraph: https://github.com/jenkins-infra/jenkins.io/tree/master/content/images/docker
• Social media tabs in all Docker packaging repositories within: https://github.com/jenkinsci
• Platform SIG pages
• Jenkins project media materials, especially ones we plan to use in May for the CDF virtual booth

[ndeloof]

I should have asked for 1$ for each use of this image :D