in_prometheus_scrape plugin missing buffer_max_size config description

[eschabell]

Bug Report

Describe the bug
Missing configuration parameter description for buffer_max_size.

To Reproduce

./fluent-bit -i prometheus_scrape -h

...
buffer_max_size      [EMPTY HERE]              
                                   > default: 10M, type: size
...

Expected behavior
Above command should show description matching docs for this plugin.

Note, already documented!

Screenshots
N/A

Your Environment

• Version used: ALL
• Configuration: ALL
• Environment name and version (e.g. Kubernetes? What version?): ALL
• Server type and version: ALL
• Operating System and version: ALL
• Filters and plugins: Prometheus Scrape input plugin

Additional context
N/A