Reserve_Data vs Reserved_Data vs Preserve_Data in parser filter

[firefart]

Bug Report

Describe the bug

https://docs.fluentbit.io/manual/pipeline/filters/parser

The docs seem to be wrong, sometimes the field is called reserve_data, on another line it's called reserved_data (with an additional d). And I guess it should be called preserve_data instead like the preserve_key field.

[patrick-stephens]

I'm going to move this to the docs repo but yeah it sounds wonky so if you can contribute a PR to update that would be good.