moved the entries up one folder, added the folder to the keywords

games/3d_city.md

@@ -0,0 +1,13 @@
+# 3d.city
+
+_WebGL version of micropolisJS._
+
+- Home: https://github.com/lo-th/3d.city
+- State: mature, inactive since 2016
+- Play: http://lo-th.github.io/3d.city/index.html
+- Keywords: simulation, browser
+- Code repository: https://github.com/lo-th/3d.city.git
+- Code language: JavaScript
+- Code license: GPL-3.0
+
+## Building