Fix typos in provider.go for ClusterLoader

[Jont828]

What type of PR is this?

/kind documentation

What this PR does / why we need it: Fix typos and missing doc entries in provider.go.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

[mboersma]

/assign @wojtek-t

[wojtek-t]

/lgtm /approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Jont828, mboersma, wojtek-t

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• ~~clusterloader2/OWNERS~~ [wojtek-t]

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