screenshot (github top 50) and statistics charts support in website output

game engines now counted as frameworks
few additions

entries/gamedev_framework_gf.md

@@ -0,0 +1,13 @@
+# Gamedev Framework (gf)
+
+- Home: https://gamedevframework.github.io/
+- State: beta 
+- Keyword: framework, 2D
+- Code repository: https://github.com/GamedevFramework/gf.git
+- Code language: C++
+- Code license: zlib
+- Code dependency: SDL
+
+## Building
+
+- Build system: CMake