Update README.md

Signed-off-by: Eden Ross Duff, MSc <rjdbcm@outlook.com>

Author: rjdbcm

README.md

@@ -4,7 +4,9 @@ Provenance workflow for OZI tooled projects.
 
 ## Inputs
 
-No action inputs but expects an artifact with a directory ``dist/`` containing the subjects to attest provenance of.
+Expects an artifact with a directory ``dist/`` containing the subjects to attest provenance of.
+
+* release-tag - release tag to upload provenance to (required)
 
 ## Permissions