add user contribution to challenge 118

Author: fturmel

content/videos/challenges/118-mastodon-fractal-tree-bot/showcase/contribution1.json

@@ -0,0 +1,9 @@
+{
+  "title": "Polite circles-maker bot",
+  "url": "https://github.com/raynauds/mastodon-bot",
+  "author": {
+    "name": "Sébastien Raynaud",
+    "url": "https://twitter.com/Chopokopx"
+  },
+  "submittedOn": "2018-11-12"
+}