Documentation

Issue https://github.com/vmware-tanzu/kubeapps/issues/1354

The goal of this proposal is to define how the new UI of Kubeapps will look like. To make collaboration easier, a Google doc is available:

https://docs.google.com/document/d/1_7k-YeegranjvW8CbvaGU_f4bCC46WrnRGIRMtMDlr8/

Also, the design is also available in Figma:

https://www.figma.com/file/q8ZXJAU2JD1riZg2c47OeE/Wireframes?node-id=0%3A1