OpenTelemetry Input Plugin - Docs update for missing configuration option descriptions.

[eschabell]

This issue is for the update PR fluent/fluent-bit#11192 solving the issue fluent/fluent-bit#11191 where 5 options were missing their descriptions.

Need to update the OpenTelemetry input plugin options table to reflect these new descriptions: https://docs.fluentbit.io/manual/data-pipeline/inputs/opentelemetry

[eschabell]

Changes to apply to table:

http2 - "Enable HTTP/2 protocol support for the OpenTelemetry receiver"
buffer_max_size - "Maximum size of the HTTP request buffer"
buffer_chunk_size - "Size of each buffer chunk allocated for HTTP requests"
tag_key - "Record accessor key to use for generating tags from incoming records"
logs_metadata_key - "Key name to store OpenTelemetry logs metadata in the record"