Add 'rarfile' to list of dependencies.

README.md

@@ -17,6 +17,7 @@ The following Python packages are needed to use this code:
 * [google-auth-oauthlib](https://google-auth-oauthlib.readthedocs.io)
 * [python-zstandard](https://python-zstandard.readthedocs.io)
 * [openpyxl](https://openpyxl.readthedocs.io)
+* [rarfile](https://github.com/markokr/rarfile)
 * [pandas](https://pandas.pydata.org)
 
 To render the website you need the following stored inside the