Inform that Tails comes with the Tails signing key

wiki/src/install/inc/steps/download.inline.html

@@ -388,6 +388,8 @@ importing keys|https://gpgtools.tenderapp.com/kb/gpg-keychain-faq/how-to-find-pu
 
 <h3>In Tails</h3>
 
+<p>Tails comes with the Tails signing key already imported.</p>
+
 <ol>
   <li>
    Open the file browser and navigate to the folder where you saved the