====== Official Kotlin tour ======

https://kotlinlang.org/docs/kotlin-tour-welcome.html

===== Hello World =====
https://kotlinlang.org/docs/kotlin-tour-hello-world.html

  * ''fun''
  * ''main()''
  * ''print() / println()''
  * ''val'' / ''var''
  * String templates
    * ''println("There are $customers customers")''

===== Basic types =====

===== Collections =====

===== Control flow =====


===== Functions =====


===== Classes =====


===== Null safety =====