Document configuration options to change output new in Falco 0.39.0

[LucaGuerra]

/area documentation

What would you like to be added:

Here https://falco.org/docs/rules/overriding/ and here https://falco.org/docs/rules/controlling-rules/ we explain how to append output to specific rules or how to enable or disable specific rules. Now we can append extra output (like "-p") with specific falco.yaml config options. Plus, we can now control the json output with a new property. Check if this is worth adding to the main documentation website (I think it is) and which section

Ref.

• new(falco): add append_output configuration option with fields and format falco#3308
• new(falco): enable CLI options with -o key={object} falco#3310
• new(falco): add json_include_message_property to have a message field without date and priority falco#3314

Why is this needed: