add CAD category

README.org

@@ -28,6 +28,11 @@ If you are using the **Nix** package manager or **NixOS**, have a look at the [[
 - [[https://rambox.pro/][Rambox]] :: Workspace browser that allows you to manage as many applications as you want
 - [[https://getsession.org/][Session]] :: End-to-end encrypted messenger that minimises sensitive metadata, designed and built for people who want absolute privacy and freedom from any form of surveillance
 
+*** Computer-Aided Design
+
+- [[https://www.freecadweb.org/][FreeCAD]] :: Open-source parametric 3D modeler made primarily to design real-life objects of any size
+- [[https://solvespace.com/][SolveSpace]] :: Free parametric 3D CAD tool
+    
 *** Desktop Environments
 
 - [[https://www.gnome.org/][GNOME]] :: Easy and elegant way to use your computer