Since the previous CR we removed squeeze (in PR #532) that can be generically emulated and expressed in terms of other low-level operations. Now the informative squeeze emulation note is plugged into the lstm section which is wrong. We should keep this note in its own squeeze section.

Considering deprecations may be expected in the future too, we should agree on how to best structure the spec for this:

• keep deprecated ops in the top-level API section: remove all the normative content and leave only the informative emulation note in place, maybe annotate the title with "deprecated"
• add a new top-level section for deprecated ops next to the API top-level

Thoughts? Is the first option better?