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>

docs/how-to/using-rocDecode-videodecode-sample.rst

@@ -76,7 +76,6 @@ The ``videodecode.cpp`` sample lets the user choose which method to use through
       - Seek criteria and seek starting point
       - Optional. Set to 1 and the frame number to start demultiplexing from that specific frame. Set to 2 and the timestamp to start demultiplexing from that specific timestamp. The seek criteria and starting point must be comma-separated (``,``). Demultiplexing begins at the first frame by default. 
 
-      
     * - ``-seek_mode``
       - Seek mode 
       - Optional. Set to 0 to seek to the previous keyframe. Set to 1 to seek to the exact frame. Seeks to previous keyframe by default.