Missing 4.1 feature documentation - Prometheus Textfile input

[eschabell]

Missing new details from 4.1 release:

Prometheus Textfile input - Ingest from .prom files

There is an existing page, but might need updates related to this release? https://docs.fluentbit.io/manual/data-pipeline/inputs/prometheus-textfile

[eschabell]

Updating Prometheus Textfile input plugin config options table based on code details found here: https://github.com/fluent/fluent-bit/blob/master/plugins/in_prometheus_textfile/prometheus_textfile.c#L359