renamed games folder to entries folder (also contained frameworks, libraries, ...) and added to the backlog

entries/battle_tanks.md

@@ -0,0 +1,19 @@
+# Battle Tanks
+
+_Fast 2D tank arcade game with multiplayer and split-screen modes._
+
+- Home: http://btanks.sourceforge.net/blog/, https://sourceforge.net/projects/btanks/
+- State: mature, inactive since 2009
+- Download: https://sourceforge.net/projects/btanks/files/
+- Platform: Windows, Linux, macOS
+- Keywords: action, arcade
+- Code repository: https://github.com/whoozle/btanks.git, https://svn.code.sf.net/p/btanks/code/ (svn)
+- Code language: C++
+- Code license: GPL-2.0
+- Assets license: Proprietary
+
+Only sources are GPL?
+
+## Building
+
+