Internals: Added Name to ImGuiDataTypeInfo + minor misc comments in BeginGroup().

imgui_internal.h

@@ -786,7 +786,8 @@ struct ImGuiDataTypeTempStorage
 // Type information associated to one ImGuiDataType. Retrieve with DataTypeGetInfo().
 struct ImGuiDataTypeInfo
 {
-    size_t      Size;           // Size in byte
+    size_t      Size;           // Size in bytes
+    const char* Name;           // Short descriptive name for the type, for debugging
     const char* PrintFmt;       // Default printf format for the type
     const char* ScanFmt;        // Default scanf format for the type
 };