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

games/rpg/arx_libertatis.md

@@ -7,11 +7,11 @@ _Arx Libertatis is a cross-platform, open source port of Arx Fatalis, a 2002 fir
 - Download: http://wiki.arx-libertatis.org/Download
 - State: mature
 - Keywords: SP
-- Code: https://github.com/arx/ArxLibertatis
-- Language(s): C++
+- Code repository: https://github.com/arx/ArxLibertatis
+- Code language: C++
 - Code license: GPL-3.0
 
 ## Building
 
-Uses CMake
+- Build system: CMake