Docs - Core api reference refresh (#669)

* Updated core docs + Doxyfile

* fixed issues, renamed a file, deleted unused files

* added hip-dev as a requirement for 7.2

* updated with Jeff's review

* updated getvideoframe description

* Update docs/reference/rocDecode-parser.rst

Co-authored-by: Leo Paoletti <164940351+lpaoletti@users.noreply.github.com>

* Update docs/how-to/using-rocDecode-video-decoder.rst

Co-authored-by: Leo Paoletti <164940351+lpaoletti@users.noreply.github.com>

* updated with Leo's feedback

* fixed a wrong link in toc

---------

Co-authored-by: Kiriti Gowda <kiritigowda@gmail.com>
Co-authored-by: Leo Paoletti <164940351+lpaoletti@users.noreply.github.com>

[ROCm/rocdecode commit: 134369824d]

projects/rocdecode/docs/tutorials/README.md

@@ -1 +0,0 @@
-Placeholder to ensure docs/tutorials folder is created.  Can remove once tutorial content is provided.