Update macOS install instructions (#2842)

Remove installing xcode command line tools, no longer necessary as installer doesn't require python
Update picture of extracted installer for new logo
Add picture of warning about downloaded files

source/docs/zero-to-robot/step-2/wpilib-setup.rst

@@ -56,12 +56,15 @@ When you download the WPILib installer, it is distributed as a disk image file `
    .. tab-item:: macOS
       :sync: macos
 
-      For this release, macOS users will need to have the Xcode Command Line Tools installed before running the installer; we are working on removing this requirement in a future release. This can be done by running ``xcode-select --install`` in the Terminal.
-
-      macOS users can double click on the downloaded ``DMG`` and then select ``WPILibInstaller`` to launch the application.
+      macOS users can double click on the downloaded ``dmg`` and then select ``WPILibInstaller`` to launch the application.
 
       .. image:: images/wpilib-setup/macos-launch.png
-         :alt: Show the macOS screen after double clicking the DMG file.
+         :alt: Show the macOS screen after double clicking the .dmg file.
+
+      If a warning is shown about WPILibInstaller being downloaded from the internet, select :guilabel:`Open`.
+
+      .. image:: images/wpilib-setup/macos-downloaded.png
+         :alt: Warning about WPILibInstaller being downloaded from the internet
 
    .. tab-item:: Linux
       :sync: linux