Lack of YAML documentation

[uob-hillmu]

The docs state that

we strongly encourage users to transition to YAML

and that Classic mode is

To be deprecated at the end of 2025.

yet there's some pages that contain little or no YAML examples. A sample:

• https://docs.fluentbit.io/manual/pipeline/inputs/prometheus-scrape-metrics
• https://docs.fluentbit.io/manual/pipeline/outputs/elasticsearch
• https://docs.fluentbit.io/manual/pipeline/outputs/loki

The last one does have two examples, but the rest (~10) are only Classic.

Fluent Bit seems to be exceedingly well documented in general, so this is both confusing and a little frustrating. What should new users use at this point, YAML or Classic?

[eschabell]

@uob-hillmu I'm going to start working on this... @patrick-stephens or @edsiper can you assign this one to me?

[eschabell]

@uob-hillmu here is a YAML doc update for the Router.

[eschabell]

@uob-hillmu here is a YAML doc update for Build with Static Configuration.

[eschabell]

@uob-hillmu here is a YAML doc update for Installation -> Kubernetes docs.

[eschabell]

@uob-hillmu here is a YAML doc update for Buffering and Storage docs.

[eschabell]

@uob-hillmu here is a YAML doc update for Scheduling and Retries doc.

[eschabell]

@uob-hillmu here is a YAML doc update for Networking docs."

[eschabell]

@uob-hillmu this PR adds YAML example to Prometheus Scrape Metrics as requested.

[eschabell]

@uob-hillmu this PR adds YAML examples to Loki output plugin docs as requested.