Add a missing newline to fix the newfile rendering

towncrier renders with `trim_blocks=True` which trims the newline at the
start of the for loop's body. This adds an additional newline which is
not trimmed, which ensures that the code blocks don't blend into each
other.

Author: pradyunsg

tools/news/template.rst

@@ -33,6 +33,7 @@
 
 {# This is the loop that generates individual entries #}
 {% for message, issue_reference in sections[section_name][type_]|dictsort(by='value') %}
+
 - {{ message }}
   {%- if type_ not in ["vendor", "process"] %} ({{ issue_reference|sort|join(', ') }}){% endif %}
 {% endfor %}