Create standalone documentation

[nachoBonafonte]

Documentation of the project is currently only added to the source code files, having standalone documentation would be great for reference. Open to any idea that can reuse existing comments in code or written specifically.

[svrnm]

Hey, I am just reviewing what we want to add as good first issues at https://github.com/open-telemetry/opentelemetry.io, should we ask for the same over there? My idea was to take some of the examples (e.g. https://github.com/open-telemetry/opentelemetry-swift/tree/main/Examples/Simple%20Exporter) and turn them into a first version of getting started, like we did it with php:

https://opentelemetry.io/docs/instrumentation/php/getting-started/

[Sherlouk]

Worth noting that SwiftPackageIndex does now support hosting DocC docs generated from Swift packages like this one.

https://blog.swiftpackageindex.com/posts/auto-generating-auto-hosting-and-auto-updating-docc-documentation/

[svrnm]

Adding this for more context here as well: There's https://github.com/open-telemetry/opentelemetry.io/issues/730 on having the docs at opentelemetry.io for "improving user experience and SEO", so I am trying to see where languages without docs (Swift, C++, Rust) are standing today.