dark-shadow: add config info about 8week pswd life

src/Jackett.Common/Definitions/dark-shadow.yml

@@ -72,6 +72,10 @@ caps:
     book-search: [q]
 
 settings:
+  - name: info_password
+    type: info
+    label: About Password Expiry
+    default: "Dark Shadow has an <b>8 week Password Expiry</b> regime. So if the Indexer has stopped working then the first thing you should do is check if your password has expired by login to the WEB site, and if necessary use the <b>Passwort anfordern</b> (<i>Request password</i>) button to renew it."
   - name: username
     type: text
     label: Username