New Website: Remove Old Content [2/3] (#15885)

* Adding new website files

Co-authored-by: Thomas Delteil <thomas.delteil1@gmail.com>
Co-authored-by: Aaron Markham <markhama@amazon.com>

* removing old content

Co-authored-by: Thomas Delteil <thomas.delteil1@gmail.com>
Co-authored-by: Aaron Markham <markhama@amazon.com>

* add license header

* fixing links and url + css

* fixing tutorials

* exclude python_docs folder when building prod site

This allows things to coexist until a following PR deletes this file.

* license header fixes

* exclude static site from license header check

* exclude static site and sphinx theme

* exclude static_site and cpp_docs from sphinx

* add licenses and excludes

* fix headers

* restore file for legacy builds

* empty commit to trigger CI

* update submodule to correct one

* delete website check

* add placeholder website check

* add placeholder website check, for reals this time

* trigger CI

* trigger PR