[LOG4J2-1855]: Add docs about maxRandomDelay
[LOG4J2-1855]: Add docs about maxRandomDelay

xnslong/logging-log4j2,apache/logging-log4j2,codescale/logging-log4j2,codescale/logging-log4j2,apache/logging-log4j2,GFriedrich/logging-log4j2,GFriedrich/logging-log4j2,codescale/logging-log4j2,xnslong/logging-log4j2,apache/logging-log4j2,xnslong/logging-log4j2,GFriedrich/logging-log4j2