Fix/improve demo documentation

[mateusoliveira43]

Describe the behavior changes introduced in this PR

I was running the Pelorus demo and decided to update the documentation on that part (but I ended up doing more and this became a big PR 😢).

The idea of this PR is to improve our documentation, focused on the Pelorus demo.

Linked Issues?

not closing ones.

Testing Instructions

Run the documentation locally, with

make dev-env
source .venv/bin/activate
mkdocs serve

and compare with our live documentation.

Depends on: #723 #690

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign etsauer for approval by writing /assign @etsauer in a comment. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[mpryc]

/test 4.10-e2e-openshift

[mateusoliveira43]

I would change the order of philosophy and getting started, what you think?

[weshayutin]

@mpryc this will likely conflict w/ https://github.com/konveyor/pelorus/pull/723/files which imho we should hurry up and merge.

[mateusoliveira43]

Applied some changes from #723

[mpryc]

/lgtm