Add change log document

CHANGES.md

+# Change log
+
+## v0.1.1
+
+- Change return type of `.upload()` to be a tuple of IDs
+- Fix DBRepo database creation failing
+
+
+## v0.1.0
+
+- Initial public release

README.md

@@ -22,3 +22,8 @@ Since the VRE/Repository Connector is currently in a proof of concept stage, sup
 It includes:
 * [InvenioRDM](https://inveniordm.docs.cern.ch/)
 * [DBRepo](https://www.ifs.tuwien.ac.at/infrastructures/dbrepo/)
+
+
+## Changes
+
+See the [changelog](./CHANGES.md) document.