A small docs update to prepare for v0.3.1-post1 (#328)

This PR updates the documentation, in preparation for changing
ReadTheDocs so that it no longer pins to `latest`.

In particular, this PR:

- Cherry picks in the AutoGraph guide
1ab07aa
- Updates the `@qjit` docstring to reflect new devices
- Adds mention of no `lambda` support to the AutoGraph guide

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Co-authored-by: David Ittah <dime10@users.noreply.github.com>