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

games/strategy/maxr.md

@@ -4,12 +4,12 @@ _A remake of the old M.A.X. by Interplay from 1996._
 
 - Home: https://www.maxr.org/
 - Download: https://www.maxr.org/docs.php?id=3
-- Code: see download
-- Language(s): C++, C
+- Code repository: (see download)
+- Code language: C++, C
 - Code license: GPL-2.0
 
 May require original game content.
 
 ## Building
 
-Uses CMake
+- Build system: CMake