Default line separation to `true`

[AndesKrrrrrrrrrrr]

When ingesting logs via DataDog the logs are malformed if appendLineSeparator is false.

appendLineSeparator = false

We get log lines of concatenated JSON objects, which aren't parsed correctly. Long lines are snipped somewhere due to log streaming. For example

{"name": "john","age":11}{"otherEvent": ["foo"]}
{"name": "jane","age":22}{"otherEvent": ["bar"]}

appendLineSeparator = true

A single JSON object per line, easy to parse, no snipping. For example:

{"name": "john","age":11}
{"otherEvent": ["foo"]}
{"name": "jane","age":22}
{"otherEvent": ["bar"]}