Onestream connector documentation update

[os-edo]

Removed Beta flag
Added documentation for loading large datasets

[learn-build-service-prod]

Learn Build status updates of commit 5226b5f:

✅ Validation status: passed

File	Status	Preview URL	Details
powerquery-docs/connectors/media/onestream/os-method-adapter-loop.png	✅Succeeded
powerquery-docs/connectors/onestream.md	✅Succeeded

For more details, please refer to the build report.

[os-edo]

@microsoft-github-policy-service agree company="Onestream software"

[prmerger-automator]

@os-edo : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change. @os-mik

[v-regandowner]

@DougKlopfenstein - Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team

[learn-build-service-prod]

Learn Build status updates of commit 94a36ab:

✅ Validation status: passed

File	Status	Preview URL	Details
powerquery-docs/connectors/media/onestream/os-method-adapter-loop.png	✅Succeeded
powerquery-docs/connectors/onestream.md	✅Succeeded

For more details, please refer to the build report.

[prmerger-automator]

PRMerger Results

Issue	Description
Added File(s)	This PR contains added files. New files require human review.
Image File	This PR added or updated an image file(s).