Merge pull request #752 from edizor/master

Update README

Author: lor6

scala-core-8/README.md

@@ -5,3 +5,4 @@
 - [The Builder Pattern in Scala](https://www.baeldung.com/scala/builder-pattern)
 - [Guide to Scala Duration and FiniteDuration](https://www.baeldung.com/scala/duration-finiteduration)
 - [Get Difference Between Two Dates](https://www.baeldung.com/scala/difference-between-two-dates)
+- [The Either Type in Scala](https://www.baeldung.com/scala/either-type)

scala-libraries-5/README.md

@@ -1,2 +1,3 @@
 ## Relevant Articles
 - [Joining Two DataFrames in Scala Spark](https://www.baeldung.com/scala/spark-joining-dataframes)
+- [Introduction to Spire](https://www.baeldung.com/scala/spire-intro)

scala3-lang-2/README.md

@@ -9,3 +9,4 @@
 - [Introduction to Macros in Scala 3](https://www.baeldung.com/scala/macros-scala-3)
 - [Difference Between NonFatal And Exception In Scala](https://www.baeldung.com/scala/nonfatal-vs-exception)
 - [Introduction to the @threadUnsafe Annotation in Scala 3](https://www.baeldung.com/scala/scala-3-threadunsafe)
+- [locally Block In Scala](https://www.baeldung.com/scala/locally-block)

zio/README.md

@@ -3,3 +3,4 @@
 - [Introduction to ZIO](https://www.baeldung.com/scala/zio-intro)
 - [Introduction to ZIO Streams](https://www.baeldung.com/scala/zio-streams-intro)
 - [Resource Handling in ZIO](https://www.baeldung.com/scala/zio-resource-handling)
+- [Different Ways to Create ZIO Effects](https://www.baeldung.com/scala/zio-effects)