[Docs/PTX] Add device tensor map init example (NVIDIA#1983)

* docs: Add device tensor map initialization example

* docs: Fix table of contents

There were quite a few empty pages. This commit makes sure that
navigation makes sense.

* docs: Spelling

Address and tensor map


Co-authored-by: Michael Schellenberger Costa <[email protected]>
Co-authored-by: Giannis Gonidelis <[email protected]>

Author: 3 people