rename fields to improve understanding, adapting maintenance.py (intermediate)

games/rpg/open_tibia.md

@@ -5,12 +5,12 @@ _Remake of Tibia_
 - Home: https://github.com/opentibia https://sourceforge.net/projects/opentibia/
 - Download: https://sourceforge.net/projects/opentibia/files/
 - State: beta, inactive since 2014
-- Code: https://github.com/opentibia
-- Language(s): C++
+- Code repository: https://github.com/opentibia
+- Code language: C++
 - Code license: GPL-2.0
 
 Based on [Tibia](http://tibia.wikia.com/wiki/CipSoft_GmbH).
 
 ## Building
 
-Uses CMake
+- Build system: CMake