* add API doc comments to goamdsmi.go
* update README and usage
* add sphinx directive to parse go doc
* fix walrus operator typos
* make docs more consistent
* add Go docs to index.md
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Signed-off-by: Arif, Maisam <Maisam.Arif@amd.com>
[ROCm/amdsmi commit: 15c32f6116]