Restructure of examples and applications

[zohimchandani]

Examples section: aim is to show how to use CUDA-Q syntax.

Applications section: aim to show various useful things you can build with CUDA-Q.

Restructure of both sections, added new ones, deleted repeated ones and condensed ones that could be condensed.

This work is in collaboration with @mawolf2023 who did most of the heavy lifting here.

At the higher level, the structure would look like

docs/sphinx
    - applications
         - cpp
         - python
    - examples
         - cpp
         - python
    - targets
         - cpp
         - python