Update linux documentation for latest release (#538)

* Update linux documentation for latest release

* Updated screenshots. Generic version number

Author: williamhaley

source/docs/getting-started/getting-started-frc-control-system/images/linux/extract-wpilib.png

@@ -214,7 +214,7 @@ WPILib Installation Guide
       .. figure:: images/linux/install-vscode.png
           :alt: Install VS-Code
 
-    **Download the WPILib release**
+    **Download the most recent WPILib release**
 
       Download the latest Linux release from https://github.com/wpilibsuite/allwpilib/releases Right-click on the downloaded archive, click "Extract Here"
 
@@ -226,7 +226,7 @@ WPILib Installation Guide
     **Moving to wpilib/2020**
 
       1. Create a directory structure in your home directory called wpilib/2020 - either from the file manager or with ``$ mkdir -p ~/wpilib/2020``
-      2. Drag the contents of WPILIB\_Linux-2020.1.1 directory to ~/wpilib/2020 or run ``$ mv -v WPILib_Linux-2020.1.1/* ~/wpilib/2020``
+      2. Drag the contents of WPILib_Linux-VERSIONUM directory to ~/wpilib/2020 or run ``$ mv -v WPILib_Linux-VERSIONUM/* ~/wpilib/2020``
 
     **Running Tools Updater**