Update install docs to use velero install instead of in-tree YAML

[skriss]

The install docs for our various supported platforms sometimes differ from each other for no apparent reason. For example, for Azure we kubectl apply the entire example folder, whereas for GCP we don't.

Additionally, we have a legacy numbering scheme on our YAML files that probably isn't necessary anymore and may just lead to confusion/annoyance. Look at possibly removing that.

cc @carlisia

[rosskukulinski]

Not saying we need to solve #52 at this time, but thought we should link the issues.

[carlisia]

Good point. This ticket could be the organization phase of moving towards an install.

[nrb]

Looking at what I may do for #52, I'm thinking the following:

• YAML examples will be entirely from the repository. If YAML is needed, users can run ark install --dry-run -o yaml (exact args and flags not necessarily final)
• Each provider's install invocation will be with instructions for preparing the necessary provider-specific steps. I'm thinking that doing provider set up like creating buckets and IAM roles/policy is out of scope for ark install - it just focuses on creating the CRDs + necessary objects in the cluster, plus the deployment. I'm not sure if I care where that goes, in light of the larger docs refactor.

@Bradamant3 The two points above seem fairly minimal to me. I can discuss further, but I think those are my main concerns at the moment.

[Bradamant3]

@nrb makes sense. Agree with the assumptions in the second point about scope for ark install. Helps a lot with planning content -- thanks!

[skriss]

Now that we have velero install, we'll standardize by updating the install docs to use this command, and largely doing away with static sample YAML.

[skriss]

Can we close this issue now?