Create README.md (eugenp#2092)

Author: pivovarit

core-java/README.md

@@ -114,3 +114,20 @@
 - [LongAdder and LongAccumulator in Java](http://www.baeldung.com/java-longadder-and-longaccumulator)
 - [Using Java MappedByteBuffer](http://www.baeldung.com/java-mapped-byte-buffer)
 - [Dynamic Proxies in Java](http://www.baeldung.com/java-dynamic-proxies)
+- [How to Copy an Array in Java](http://www.baeldung.com/java-array-copy)
+- [Introduction to JDBC](http://www.baeldung.com/java-jdbc)
+- [Guide to CopyOnWriteArrayList](http://www.baeldung.com/java-copy-on-write-arraylist)
+- [Period and Duration in Java](http://www.baeldung.com/java-period-duration)
+- [Converting a Stack Trace to a String in Java](http://www.baeldung.com/java-stacktrace-to-string)
+- [Guide to the Java Phaser](http://www.baeldung.com/java-phaser)
+- [Count Occurrences of a Char in a String](http://www.baeldung.com/java-count-chars)
+- [Java Double Brace Initialization](http://www.baeldung.com/java-double-brace-initialization)
+- [The StackOverflowError in Java](http://www.baeldung.com/java-stack-overflow-error)
+- [Split a String in Java](http://www.baeldung.com/java-split-string)
+- [Introduction to Java Serialization](http://www.baeldung.com/java-serialization)
+- [How to Remove the Last Character of a String?](http://www.baeldung.com/java-remove-last-character-of-string)
+- [Guide to Synchronized Keyword in Java](http://www.baeldung.com/java-synchronized)
+- [ClassNotFoundException vs NoClassDefFoundError](http://www.baeldung.com/java-classnotfoundexception-and-noclassdeffounderror)
+- [Guide to UUID in Java](http://www.baeldung.com/java-uuid)
+- [How to Get the Last Element of a Stream in Java?](http://www.baeldung.com/java-stream-last-element)
+- [Guide to Escaping Characters in Java RegExps](http://www.baeldung.com/java-regexp-escape-char)