Update README

Author: mfherbst

README.md

@@ -140,7 +140,7 @@ of new families. These are indicated in the *Available Pseudopotentials*
 section above.
 
 ### Releasing a new version
-- Update the `VERSION` variable in `scripts/make_artifacts.jl`
+- Update the `LIBRARY_VERSION` variable in `scripts/make_artifacts.jl`
 - Make a tag of the form `v0.0.0` and push the tag
 - The CI will effectively call
   ```sh