Add comments and rename variables to make them more clear

Co-authored-by: Lukas Tenbrink <[email protected]>

Author: Chkoupinator

SConstruct

@@ -39,10 +39,10 @@ env = SConscript("godot-cpp/SConstruct", {"env": env, "customs": customs})
 
 env.Append(CPPPATH=["src/"])
 sources = []
-for root, folders, files in os.walk("src"):
-    if root.endswith("gen"):
-        continue
-    sources += Glob(os.path.join(root, "*.cpp"))
+# Recursively add every .cpp file in the src directory.
+for folder_path, _, _ in os.walk("src"):
+    if not folder_path.endswith("/gen"): # The doc data in src/gen is added later
+        sources += Glob(os.path.join(folder_path, "*.cpp"))
 
 if env["target"] in ["editor", "template_debug"]:
     try: