Introduction of OS platform attribute

[thompson-tomo]

Area(s)

area:os

Is your change request related to a problem? Please describe.

I want to easily see all my logs from linux machines, just like i can with ECS.

Describe the solution you'd like

Introduction of a new field -> os.platform which is a mapping of highlevel OS groups ie Linux, Windows etc

Describe alternatives you've considered

No response

Additional context

https://www.elastic.co/guide/en/ecs/current/ecs-os.html

[thompson-tomo]

Note, a dotnet detector has been logged as open-telemetry/opentelemetry-dotnet-contrib#1958