Readme update.

README.md

@@ -68,4 +68,19 @@
 ### DAY 14 - Polymeric lanternfish
 
 - [part1](14/part1.php)
-- [part2](14/part2.php)
+- [part2](14/part2.php)
+
+### DAY 15 - Chitons
+
+- [part1](15/part1.php)
+- [part2](15/part2.php)
+
+### DAY 16 - TODO
+
+- [part1](16/part1.php)
+- [part2](16/part2.php)
+
+### DAY 17 - Trick shoot
+
+- [part1](17/part1.php)
+- [part2](17/part2.php)