CNCF logo / arwork URL update in https://microcks.io/resources/

[yada]

Update the URL to the CNCF GitHub (note the path change).

from: https://github.com/cncf/artwork/blob/main/examples/sandbox.md#microcks-logos

to: https://github.com/cncf/artwork/blob/main/examples/sandbox_l-r.md#microcks-logos