Continued SDK Documentation Improvements

Many MDL APIs persist in CONNECT.  Often, there is a 21^st century class that offers similar or better functionality.  However, it's not obvious from the MDL documentation that a C++ alternative may exists.

For example, the mdlDisplayPath_api continues from V8 to CONNECT.  In CONNECT there is also the DisplayPath class.  There is not indication in the former that the latter exists.

It would be useful to provide a hint in an MDL API that a C++ API also exists.

Corrections of the current contents, all the way back to the mdlXXX functions.

We would like to see more code snippets

Each section of the API should provide an Overview and present related create, read, update, and delete (CRUD) functionality grouped together to make it more intuitive on what we may need to call/access next.