Manual tests: test .torrent files.

wiki/src/contribute/release_process/test.mdwn

@@ -278,6 +278,15 @@ at the application level:
   8. Repeat for the USB image, except the URL for step (3) is:
      <https://tails.boum.org/install/download/>
 
+# Torrents
+
+Make sure that the .torrent files we advertise for this release can be
+used to download the *full* images:
+
+* ISO
+
+* USB image
+
 # Real (non-VM) hardware
 
 `[can't-automate]`