Add documentation for `oai` / improve discoverability

[banool]

Currently when you search for oai in the docs, nothing comes up: https://docs.rs/poem-openapi/latest/poem_openapi/?search=oai. This is one of the most important macros for the Poem OpenAPI crate but it's hard to figure out how to use it. Could we add documentation for it if it doesn't exist and an alias so you can search for it by oai?

[banool]

I see we have docs at poem-openapi/src/docs/openapi.md, we could make an alias to go search there at least.

[sunli829]

I don't know how to do it. 😂

[banool]

lol I can take a look at doing it, stay posted

[banool]

For my future self: https://doc.rust-lang.org/rustdoc/advanced-features.html. I'll take a look at this next week.

[github-actions[bot]]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[github-actions[bot]]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[github-actions[bot]]

This issue was closed because it has been stalled for 5 days with no activity.