[DOCS] Arrange items in the API reference in alphabetical order

[sekikn]

Did you read the Contributor Guide?

• Yes, I have read Contributor Rules and Contributor Development Guide

Is this PR related to a JIRA ticket?

• No, this is a documentation update. The PR name follows the format [DOCS] my subject.

What changes were proposed in this PR?

Currenly, the items in the API reference seems to be ordered randomly, and it makes difficult for users to find the function they need. It is more user-friendly if they were arranged in alphabetical order.

How was this patch tested?

Ran mkdocs serve locally and made sure that the API docs were fixed as expected.

Did this PR include necessary documentation updates?

• Yes, I have updated the documentation update.