doc(2018 day-14): capture special instructions for running Day 14

Author: developher-net

README.md

@@ -1,3 +1,9 @@
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+
+### Special Instructions
+
+#### Day 14
+Day 14 is fast but needs more memory to complete. Run node with 4GB of heap space:
+`node --max_old_space_size=4096 index.js`