ci: compare message format

2020-08-05 14:17:52 +01:00 · 2020-08-05 14:17:52 +01:00 · e634239f6d
--- a/.versionrc
+++ b/.versionrc
@ -0,0 +1,3 @@
+{
+  "compareUrlFormat": "{{repoUrl}}/compare/{{previousTag}}...{{currentTag}}"
+}