Merge pull request #1577 from RannelT/master

Update on README.md

Author: lor6

scala-core-modules/scala-core-8/README.md

@@ -6,3 +6,4 @@
 - [Different Ways to Reverse a Sequence in Scala](https://www.baeldung.com/scala/reverse-sequence)
 - [Transforming a List of Futures Ignoring Failures](https://www.baeldung.com/scala/transform-list-futures-ignore-failures)
 - [Difference Between Braces and Parentheses in Scala](https://www.baeldung.com/scala/braces-vs-parentheses)
+- [Stackable Trait Pattern in Scala](https://www.baeldung.com/scala/stackable-trait-pattern)

scala-core-modules/scala-strings-2/README.md

@@ -5,3 +5,4 @@ This module contains articles about Scala's Strings.
 ### Relevant Articles:
 -  [How to Check if a String Is Null or Empty in Scala](https://www.baeldung.com/scala/string-test-null-empty)
 -  [Convert From Camel Case to Snake Case in Scala](https://www.baeldung.com/scala/camel-snake-case-automatic-conversion)
+-  [Convert Multiple Spaces Into a Single Space in Scala](https://www.baeldung.com/scala/multiple-spaces-to-single-space)

zio-2/README.md

@@ -1,3 +1,4 @@
 ### Relevant Articles: 
 - [Test Aspects in ZIO Test](https://www.baeldung.com/scala/zio-test-aspects)
 - [Introduction to ZIO Json](https://www.baeldung.com/scala/zio-json)
+- [Logging in ZIO Applications](https://www.baeldung.com/scala/zio-logging)