Add dask operator

[bstadlbauer]

Tracking issue

#427

Describe your changes

Adds:

• dask operator deployment to the helm chart
• Notes about dask to the top-level README.md
• Description on how to setup dask backend plugin

Check all the applicable boxes

• I updated the documentation accordingly.
• All new and existing tests passed.
• All commits are signed-off.

Screenshots

Note to reviewers

Do I also need to add the dask operator deployment to kustomize?

[bstadlbauer]

@hamersaw Is there also a need to a kustomize deployment for the dask operator?

[hamersaw]

@hamersaw Is there also a need to a kustomize deployment for the dask operator?

I believe we are deprecating kustomize support, so I do not think it is necessary.

cc @eapolinario can you confirm?

[eapolinario]

@hamersaw Is there also a need to a kustomize deployment for the dask operator?

I believe we are deprecating kustomize support, so I do not think it is necessary.

cc @eapolinario can you confirm?

That's correct. We talked about it, so no need to update the kustomize deployments to support this.