[2020] add adventofcode event

Author: exoji2e

_events/2020-12-01-advent_of_code.md

@@ -0,0 +1,14 @@
+---
+layout: events
+title: Advent of Code 2020
+place: "adventofcode.com"
+---
+
+The Advent calendar Advent of Code starts the _1st of December 06:00 CET_.
+
+Until the 25th of December a **new programming puzzle** is released each day at: [https://adventofcode.com/](https://adventofcode.com/)
+
+Code@LTH has a private leaderboard, where you can compete against other Code@LTH members in solving the puzzles as fast as possible (or perhaps the main competition is about how early you manage to get out of bed). 
+
+Join our leaderboard with the code: `107707-7795f557` at [https://adventofcode.com/2020/leaderboard/private](https://adventofcode.com/2020/leaderboard/private).
+