**What**
- Add new flags to toggle the name, instance, and timestamp fields.
Additionally, the new `time-format` also allows controlling the actual
timestamp format.
- Also provide the log format flag to allow printing the output as JSON,
key-values, or the plain format. This should make it easy to integrate
with other tools, like JQ etc.
Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>