Fix BurstFilter documentation regarding the level parameter (#3983)

Co-authored-by: Volkan Yazıcı <volkan@yazi.ci>

Author: mlangc

src/site/antora/modules/ROOT/pages/manual/filters.adoc

@@ -385,8 +385,7 @@ Timestamp filters use the timestamp of log events to decide whether to accept th
 [#BurstFilter]
 ==== `BurstFilter`
 
-The `BurstFilter` limits the rate of log events.
-The rate limit is only applied to log events less severe than a configured log level.
+The `BurstFilter` limits the rate of log events at or below a configured severity level.
 
 Besides the <<common-configuration-attributes,common configuration attributes>>,
 the `BurstFilter` supports the following parameters:
@@ -399,8 +398,8 @@ the `BurstFilter` supports the following parameters:
 | level
 | link:../javadoc/log4j-api/org/apache/logging/log4j/Level.html[`Level`]
 | link:../javadoc/log4j-api/org/apache/logging/log4j/Level.html#WARN[`WARN`]
-| The rate limit only applies to log events less severe than this level.
-Events at least as severe as this level will always match.
+| The rate limit is only applied up until and including this level.
+Events more severe than this level will always match.
 
 | rate
 | `float`