HTTP Header filtering documentation addition

[szczygiel-m]

No description provided.

[github-actions]

✅ Benchmark comparison: PASSED

Metric	Status	Change
consumer.HermesConsumerBenchmark.benchmarkConsumingThroughput (thrpt)	✅ PASS	↓ 0.73%
consumer.HermesConsumerBenchmark.benchmarkConsumingThroughput (thrpt) - gc.alloc.rate.norm	✅ PASS	↑ 0.20%
consumer.HermesConsumerFilteringBenchmark.benchmarkConsumingThroughput (thrpt)	✅ PASS	↓ 0.01%
consumer.HermesConsumerFilteringBenchmark.benchmarkConsumingThroughput (thrpt) - gc.alloc.rate.norm	✅ PASS	↑ 0.37%
frontend.HermesServerBenchmark.benchmarkPublishingLatency (sample)	✅ PASS	↑ 0.04%
frontend.HermesServerBenchmark.benchmarkPublishingLatency (sample) - gc.alloc.rate.norm	✅ PASS	↑ 0.34%
frontend.HermesServerBenchmark.benchmarkPublishingThroughput (thrpt)	✅ PASS	↓ 5.10%
frontend.HermesServerBenchmark.benchmarkPublishingThroughput (thrpt) - gc.alloc.rate.norm	✅ PASS	↓ 0.33%