Prefix newline before each item in changelog

The changelog is intended to be edited, but it's more convenient this
way (especially if you're like me, using Vim and '{' and '}' as major
means of moving around.

src/include/release.sh

@@ -165,7 +165,7 @@ _vbump_gitmsg() {
     echo ""
     git_fact reldiff \
       | sed '
-            s/^[a-f0-9]\{7\} / *  &/; t PATHS
+            s/^[a-f0-9]\{7\} /\n *  &/; t PATHS
             s/^/        /
             :PATHS
         '