Flattened out page structure for improved navigability.
* Change Table of Contents
* Update the install guides for windows and linux
* Removed extraneous index pages
* GPU architecture pages duplicate entries removed
* spack page cleanup
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Co-authored-by: Sam Wu <samwu103@amd.com>
Co-authored-by: Saad Rahim (AMD) <44449863+saadrahim@users.noreply.github.com>