[TODO] For DITA API docs, constructors need to be documented for each class

[yamasite]

What needs to be improved?

The CURRENT API doc lacks constructor info:

How to improve?

Constructors need to be documented for each class. For example:

https://docs.microsoft.com/en-us/java/api/com.microsoft.azure.sdk.iot.service.authenticationmechanism?view=azure-java-stable