Adjust how PV source types are documented.

[pl-gideon]

Link to documentation and OpenAPI spec instead of maintaining separately.

Related Issue(s):

Closes #

Proposed Changes:

For inclusion in changelog (if applicable):

Client does not require a new release to support additional PV source types.

Not intended for changelog:

Diff of User Interface

Old behavior:

Client requires a new release to support additional PV source types.

New behavior:

Client does not require a new release to support additional PV source types.

• Validate source types in CLI with API instead of click.Option.
• Refer to Developer Center documentation in docstrings and CLI --help instead of maintaining separately

PR Checklist:

• This PR is as small and focused as possible
• If this PR includes proposed changes for inclusion in the changelog, the title of this PR summarizes those changes and is ready for inclusion in the Changelog.
• I have updated docstrings for function changes and docs in the 'docs' folder for user interface / behavior changes
• This PR does not break any examples or I have updated them

(Optional) @mentions for Notifications: