Update README with only docker compose example
Update README with only docker compose example

At the moment, `dabs` don't seem to work as well as the fact that there
hasn't been much development since the experimental announcement of the
DAB format.

Removing it from the README makes the example clearer as well as more
direct / informative.

rupalibehera/kompose,skippbox/kompose,surajnarwade/kompose,surajnarwade/kompose,procrypt/kompose,ashetty1/kompose,cdrage/kompose,skippbox/kompose,kubernetes/kompose,containscafeine/kompose,procrypt/kompose,kadel/kompose,kubernetes/kompose,ashetty1/kompose,containscafeine/kompose,ashetty1/kompose,rupalibehera/kompose,cdrage/kompose,rupalibehera/kompose,skippbox/kompose,surajnarwade/kompose,kadel/kompose,procrypt/kompose,containscafeine/kompose