Advertise CNCF sandbox status in armadaproject.io & project documentation

[jayofdoom]

Now that we are a CNCF sandbox project, we should indicate it on our web presence and readmes.

We should, at a minimum:

• Add a CNCF badge / sandbox badge to our above-the-fold main page or a blurb about being sandbox if a badge doesn't exist
• Ensure top-level project readmes indicate we are CNCF sandbox
• If the news page exists by the time this issue is address, ensure a news item exists about our selection to the CNCF sandbox

[dave-gantenbein]

Hey team! Please add your planning poker estimate with Zenhub @dejanzele @jayofdoom @kannon92 @richscott

[dave-gantenbein]

Please add your planning poker estimate with Zenhub @suprjinx