feat docs: start release notes for v3.0

Tests: протестировано CI
commit_hash:9227355b5a50762b8e11e69c3c2c44a74d75d2e1

Author: apolukhin

.mapping.json

@@ -4654,6 +4654,7 @@
   "scripts/docs/en/userver/redis.md":"taxi/uservices/userver/scripts/docs/en/userver/redis.md",
   "scripts/docs/en/userver/requests_in_flight.md":"taxi/uservices/userver/scripts/docs/en/userver/requests_in_flight.md",
   "scripts/docs/en/userver/roadmap_and_changelog.md":"taxi/uservices/userver/scripts/docs/en/userver/roadmap_and_changelog.md",
+  "scripts/docs/en/userver/roadmap_and_changelog_v1.md":"taxi/uservices/userver/scripts/docs/en/userver/roadmap_and_changelog_v1.md",
   "scripts/docs/en/userver/security_changelog.md":"taxi/uservices/userver/scripts/docs/en/userver/security_changelog.md",
   "scripts/docs/en/userver/service_monitor.md":"taxi/uservices/userver/scripts/docs/en/userver/service_monitor.md",
   "scripts/docs/en/userver/sql_files.md":"taxi/uservices/userver/scripts/docs/en/userver/sql_files.md",

scripts/docs/en/userver/kafka.md

@@ -1,6 +1,6 @@
  ## Apache Kafka
 
-**Quality:** @ref QUALITY_TIERS "Golden Tier".
+**Quality:** @ref QUALITY_TIERS "Platinum Tier".
 
 🐙 **userver** provides access to Apache Kafka Brokers via
 two independent interfaces: @ref kafka::ProducerComponent and