Add pagination parameters to API docs

What does this MR do?

Adds lines to the docs to indicate how to use the pagniation paremters that are part of this API. These are present in the code in the API definition with the use :pagination lines but thats not in the docs so readers may not know to do it.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because docs only.
• Documentation (if required)
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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

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• Label as security and @ mention @gitlab-com/gl-security/appsec
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