chore: Add comptime docs

[jfecher]

Description

Problem*

Summary*

Most comptime features checked the "Documentation to be submitted in a separate PR" box. This is that PR.

Additional Context

Draft because I haven't documented each function in std::meta yet and want to see the docs preview.

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

Changes to Brillig bytecode sizes

Generated at commit: b5a7bd77ade9844cb86eb22ed45c54aa8f269d86, compared to commit: 38fe9dda111952fdb894df90a319c087382edfc9

There are no changes in circuit sizes

[github-actions]

🚀 Deployed on https://66c8cd459d7767e957ca9839--noir-docs.netlify.app

[TomAFrench]

Looks good. Can we put the examples (especially the larger ones) into snippets to avoid them becoming stale?

[jfecher]

@TomAFrench do we have a way to wrap tests like that? Since tests must be a single function currently.

I guess maybe they can be in their own private module in the stdlib?

[michaeljklein]

@jfecher I would prefer to avoid adding them in the stdlib to avoid making nargo bigger. Why does each test need to be a single function?

[jfecher]

Why does each test need to be a single function?

Because all #[test]s refer to a single function, while many of these examples have additional functions, structs, or traits. We could expose them all but then the test name would be exposed too. I wish we could have snippets in the docs be checked automatically without placing them in the stdlib as well.

[TomAFrench]

do we have a way to wrap tests like that? Since tests must be a single function currently.

I'm not sure I follow. A snippet can contain arbitrary content so we just need to place the examples into a program which will be checked that it compiles successfully and then we can pull out the section of code we want to display. An example of this is the // docs:start:new_example snippet in noir_test_success/bounded_vec

[jfecher]

Ok, I've moved as many snippets as I can through docs. The ones I did not move either:

• Used println internally (execution ordering example)
• Had text around the examples explaining specific items in the examples (x and y) which could implicitly break if the example were changed elsewhere without updating the docs (unquote example).

The make_trait_impl example is made a bit worse by the formatter and using crate::meta instead of std::meta but is still usable.