Add kindergarten-garden and run-length-encoding to settings.gradle

exercises/settings.gradle

 include 'hexadecimal'
 include 'hello-world'
 include 'isogram'
+include 'kindergarten-garden'
 include 'largest-series-product'
 include 'linked-list'
 include 'list-ops'
 include 'robot-name'
 include 'robot-simulator'
 include 'roman-numerals'
+include 'run-length-encoding'
 include 'saddle-points'
 include 'scrabble-score'
 include 'secret-handshake'