add spaces to PR template

Author: story645

.github/PULL_REQUEST_TEMPLATE.md

@@ -11,6 +11,8 @@ Also please summarize the changes in the title, for example "Raise ValueError on
 non-numeric input to set_xlim" and avoid non-descriptive titles such as "Addresses
 issue #8576".
 -->
+
+
 ## PR checklist
 <!-- Please mark any checkboxes that do not apply to this PR as [N/A].-->