Add changelog entry for PR #2330

Author: ppkarwasz

src/changelog/.2.x.x/2330_add_faster_web_app_context_map.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<entry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="http://logging.apache.org/log4j/changelog"
+       xsi:schemaLocation="http://logging.apache.org/log4j/changelog https://logging.apache.org/log4j/changelog-0.1.3.xsd"
+       type="added">
+  <issue id="2330" link="https://github.com/apache/logging-log4j2/pull/2330"/>
+  <description format="asciidoc">Add a faster `ThreadContextMap` for web app users: `org.apache.logging.log4j.internal.map.StringArrayThreadContextMap`.</description>
+</entry>