Merge pull request #783 from edizor/master

Update README.md

Author: lor6

scala-core-8/README.md

@@ -6,3 +6,4 @@
 - [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)
+- [Understanding the Differences: reduceLeft, reduceRight, foldLeft, foldRight, scanLeft, and scanRight in Scala](https://www.baeldung.com/scala/reduce-fold-scan-left-right)