Update install_desktop.md

Author: MMathisLab

docs/install_desktop.md

@@ -25,3 +25,5 @@ Note, you can also just run the test:
 `dlc-live-test`
 
 If installed properly, this script will i) create a temporary folder ii) download the full_dog model from the [DeepLabCut Model Zoo](http://www.mousemotorlab.org/dlc-modelzoo), iii) download a short video clip of a dog, and iv) run inference while displaying keypoints. v) remove the temporary folder.
+
+Please note, you also should have curl installed on your computer (typically this is already installed on your system), but just in case, just run `sudo apt install curl`