[deviantart] also search journals for sta.sh links (#712)

when 'extra' is enabled

docs/configuration.rst

@@ -576,7 +576,8 @@ extractor.deviantart.extra
 =========== =====
 Type        ``bool``
 Default     ``false``
-Description Download extra Sta.sh resources from description texts.
+Description Download extra Sta.sh resources from
+            description texts and journals.
 
             Note: Enabling this option also enables deviantart.metadata_.
 =========== =====

gallery_dl/extractor/deviantart.py

@@ -123,6 +123,10 @@ class DeviantartExtractor(Extractor):
                 journal = self.api.deviation_content(deviation["deviationid"])
                 yield self.commit_journal(deviation, journal)
 
+                if self.extra:
+                    deviation["description"] = \
+                        deviation.get("description", "") + journal["html"]
+
             if self.extra:
                 for match in DeviantartStashExtractor.pattern.finditer(
                         deviation.get("description", "")):