config: Top-level functions

[pellared]

Currently there are two config packages:

• go.opentelemetry.io/contrib/config/v0.2.0
• go.opentelemetry.io/contrib/config/v0.3.0

The user should be able to have functions like LoadYAML in go.opentelemetry.io/contrib/config which gives the possibility to setup the OTel Go SDK without knowing what is the exactly file-version in the OTel config file.

Maybe go.opentelemetry.io/contrib/config/v[X.Y.Z] should be even internal?

Related to:

• config: separate schema version support into separate directories #6412

[pellared]

Or maybe we should just support the latest version? Alternativly we could leave as it is until v1.0 of file-version.

[MrAlias]

I think the original motivation was to help in migration when there are breaking changes: #6412

I'm not sure we can accomplish that without these separate packages.

It might also not make sense to merge after 1.0 if the config stability guarantees do not guarantee the rendered config's stability: open-telemetry/opentelemetry-configuration#89