Scorecard move alpha

[jmccormick2001]

Description of the change:
This PR moves 'scorecard alpha' to just 'scorecard', essentially removing the 'alpha' from the scorecard package path. It updates the website CLI docs since those are generated based on the command structure.

After this PR merges, users of scorecard will now just use 'operator-sdk scorecard' instead of 'operator-sdk alpha scorecard'.

Motivation for the change:

the new Scorecard formerly known as the 'alpha' version is being promoted to the standard scorecard command.

Checklist

If the pull request includes user-facing changes, extra documentation is required:

• [ x] Add a new changelog fragment in changelog/fragments (see changelog/fragments/00-template.yaml)
• [x ] Add or update relevant sections of the docs website in website/content/en/docs

[joelanford]

/lgtm

when ci passes