Merge pull request #13956 from edizor/master

Update README

core-java-modules/core-java-20/README.md

@@ -1,2 +1,2 @@
 ## Relevant Articles
-- TBD
+- [Scoped Values in Java 20](https://www.baeldung.com/java-20-scoped-values)

core-java-modules/core-java-arrays-operations-basic/README.md

@@ -11,3 +11,4 @@ This module contains articles about Java array fundamentals. They assume no prev
 - [Removing the First Element of an Array](https://www.baeldung.com/java-array-remove-first-element)
 - [Extending an Array’s Length](https://www.baeldung.com/java-array-add-element-at-the-end)
 - [Initializing a Boolean Array in Java](https://www.baeldung.com/java-initializing-boolean-array)
+- [Find the Index of an Element in a Java Array](https://www.baeldung.com/java-array-find-index)

core-java-modules/core-java-char/README.md

@@ -4,3 +4,4 @@ This module contains articles about Java Character Class
 
 ### Relevant Articles: 
 - [Character#isAlphabetic vs. Character#isLetter](https://www.baeldung.com/java-character-isletter-isalphabetic)
+- [Difference Between Java’s “char” and “String”](https://www.baeldung.com/java-char-vs-string)

core-java-modules/core-java-perf/README.md

@@ -14,3 +14,4 @@ This module contains articles about performance of Java applications
 - [JMX Ports](https://www.baeldung.com/jmx-ports)
 - [Calling JMX MBean Method From a Shell Script](https://www.baeldung.com/jmx-mbean-shell-access)
 - [External Debugging With JMXTerm](https://www.baeldung.com/java-jmxterm-external-debugging)
+- [Create and Detect Memory Leaks in Java](https://www.baeldung.com/java-create-detect-memory-leaks)

core-java-modules/core-java-string-operations-5/README.md

@@ -8,3 +8,5 @@
 - [Convert String to String Array](https://www.baeldung.com/java-convert-string-to-string-array)
 - [String Interpolation in Java](https://www.baeldung.com/java-string-interpolation)
 - [Guide to Splitting a String by Whitespace in Java](https://www.baeldung.com/java-splitting-a-string-by-whitespace)
+- [Check if the First Letter of a String Is a Number](https://www.baeldung.com/java-check-if-string-starts-with-number)
+- [Print “” Quotes Around a String in Java](https://www.baeldung.com/java-string-print-quotes)