backlink added

Author: collaboratewithakash

core-kotlin-modules/core-kotlin-10/README.md

@@ -7,4 +7,5 @@
 - [Breadth-First Search Algorithm in Kotlin](https://www.baeldung.com/kotlin/bfs-graphs)
 - [Calling Private Methods of a Class From Outside the Class](https://www.baeldung.com/kotlin/private-methods-outside-class)
 - [Pass a Function as Parameter to Another in Kotlin](https://www.baeldung.com/kotlin/function-parameter-high-order)
+- [Accessing Methods Outside Companion Object in Kotlin](https://www.baeldung.com/kotlin/companion-object-external-methods)