Update update-document.md

[srivardhanrr]

added 'data: {}' parameter in updateDocument function in update-document.md

What does this PR do?

This PR updates the update-document.md doc. It adds the 'data: {}' parameter in updateDocument function which is required but missing in the code snippet.

Test Plan

Only Docs were updated.

Checklist

• [ Y] Have you read the [Contributing Guidelines on issues]
• [ N] If the PR includes a change to an API's metadata (desc, label, params, etc.), does it also include updated API specs and example docs?

[stnguyen90]

Unfortunately, we don't want to add this at the moment. If you wish to contribute as part of Hacktoberfest, please look for issues labeled "hacktoberfest".