[Streams] Document new wired streams endpoints #5139
Description
Wired streams will have two endpoints in serverless and 9.4, logs.otel and logs.ecs.
Need to note for current users that the the /logs endpoint will be deprecated in 9.4 and serverless.
The current table on wired streams field naming still applies to the otel endpoint, but the ecs endpoint won't be normalized (the field names in the ECS column are what the fields will be).
Contact: @mohamedhamed-ahmed