Add CAD software to Windows playbook

The `autodesk-fusion360` and `prusiaslicer` roles are added to the
`Windows.yaml` playbook but disabled by default behind the
`install_cad_apps` flag. To enable them create a `~/.config/local.yaml`
file with the following:

```yaml
- import_playbook: local/Windows.yaml
  vars:
    install_cad_apps: true
```

Windows.yaml

@@ -1,6 +1,9 @@
 ---
 - hosts: windows
 
+  vars:
+    install_cad_apps: false
+
   roles:
     - role: git
     - role: powershell
@@ -25,3 +28,8 @@
     - role: obsidian
     - role: powertoys
     - role: windows-terminal
+
+    - role: autodesk-fusion360
+      when: install_cad_apps
+    - role: prusaslicer
+      when: install_cad_apps