Smart contract costs best practices (#763)

* Smart contract costs best practices

* Update to bump_alloc and add state-* type section

* Fix CI by updating py version to 3.12 to match Sphinx container

* Apply suggestions from code review

Co-authored-by: Doris Benda <[email protected]>

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Co-authored-by: Kasper Dissing Bargsteen <[email protected]>
Co-authored-by: Doris Benda <[email protected]>

Author: 3 people