docs: Add WoeUSB as an alternative tool to burn Windows USB images

By far WoeUSB is one of the few applications that support Windows image
and runs on GNU/Linux so I assume it is worth to mention it.  Additional
line wrapping is made to comply to the code conventions.

Signed-off-by: 林博仁 <Buo.Ren.Lin@gmail.com>

docs/USER-DOCUMENTATION.md

@@ -15,7 +15,7 @@ images, usually available from the image publishers themselves.
 Images known to require special treatment:
 
 - Microsoft Windows (use [Windows USB/DVD Download Tool][windows-usb-tool], or
-  [Rufus][rufus]).
+  [Rufus][rufus], or [WoeUSB][woeusb]).
 
 - Windows 10 IoT (use the [Windows 10 IoT Core Dashboard][windows-iot-dashboard])
 
@@ -224,3 +224,4 @@ platforms.
 [rufus]: https://rufus.akeo.ie
 [unetbootin]: https://unetbootin.github.io
 [windows-iot-dashboard]: https://developer.microsoft.com/en-us/windows/iot/downloads
+[woeusb]: https://github.com/slacka/WoeUSB

lib/shared/messages.js

@@ -60,7 +60,9 @@ module.exports = {
       'It looks like you are trying to burn a Windows image.\n\n',
       'Unlike other images, Windows images require special processing to be made bootable.',
       'We suggest you use a tool specially designed for this purpose, such as',
-      '<a href="https://rufus.akeo.ie">Rufus</a> (Windows) or Boot Camp Assistant (macOS).'
+      '<a href="https://rufus.akeo.ie">Rufus</a> (Windows),',
+      '<a href="https://github.com/slacka/WoeUSB">WoeUSB</a> (Linux),',
+      'or Boot Camp Assistant (macOS).'
     ].join(' ')),
 
     missingPartitionTable: _.template([