### Description
revise example C++ code of using file path.
normalize the example code to use macros `ORTCHAR_T` and `ORT_TSTR`
defined in onnxruntime_c_api.h so that the code works in both Windows
and UNIX.
This PR resolves#14859
* Skeleton for PyTorch inference page
* Add outline
* Add different inference options
* Added section on ONNXRuntime
* Refine title
* Minor reword
* Update after review
* Minor edits
* Add link to get started
* Clarify intro text
* Add review improvements
* initial setup and rename "how to" to "setup"
* move API to main nav
* move api to main nav
* add get starated, rework nav order
* rename to install move mds out of install section
* update api nav and home page
* add install docs and python qs updates
* python get started work
* remove c and obj c for now
* move java, python, and obj-c docs under api folder
* move java api html to iframe (ugh)
* remove api docs w/o details, move api text getstar
* remove api docs wo detail updates get started
* remvoe iframes
* move eco system to main nav
* fix api buttons
* added more examples moved intro to ORT
* fix links
* fix get started titles
* fix get started titles
* fix more links
* fix more links
* more link fixes
* fix nav remove inferencing and training subnav
* fix top nav remove inference and training nav
* fix title
* fix tutorials nav hierarchy
* fix python api button
* add tenorflow keras example
* fix quickstart toc
* add imports fix spacing
* fix links
* update nav and python get started page
* move ort training example, add coming soon for iot
* update C# get started
* fix spacing on quantization
* Add some js get started content
* fix formatting
* fix typo
* removed onnx-pytorch and onnx-tf
* updated pip install torch and added links iot page
* added pytorch tutorial heirarchy
* updated web to docs soon added release blog link
* add web link
