Update v3.0.3.rst (#619)

Added note about SVG support and corrected typo

docs/releases/v3.0.3.rst

@@ -9,7 +9,12 @@ Bug fixes
 
 * Support SVG images.
 
-* Fix bug that happens when ordering child pages by Classifier, if a child page contains muliple ClassifierTerms belonging to that Classifier.
+* Fix bug that happens when ordering child pages by Classifier, if a child page contains multiple ClassifierTerms belonging to that Classifier.
+
+Upgrade considerations
+----------------------
+
+* As described in the `Wagtail documentation <https://docs.wagtail.org/en/stable/topics/images.html#id8>`_, enabling SVG support requires adding the following to the Django settings file: ``WAGTAILIMAGES_EXTENSIONS = ["gif", "jpg", "jpeg", "png", "webp", "svg"]``.
 
 
 Thank you!