Update README.md

Author: jackton1

README.md

@@ -5,7 +5,7 @@
 semver-diff
 -----------
 
-Get the difference between two semantic versions using [semver-tool](https://github.com/fsaintjacques/semver-tool)
+Get the difference between your previous tagged semantic version and the latest tag using [semver-tool](https://github.com/fsaintjacques/semver-tool)
 
 ```yaml
 name: Get semver diff