docs: Add basic instructions to README

README.rst

@@ -3,10 +3,19 @@ voraus Template Updater
 ===============================
 
 
-A CLI to keep cookiecutter-based projects up-to-date.
+A CLI to keep `cruft <https://cruft.github.io/cruft/>`_/ `cookiecutter <https://cookiecutter.readthedocs.io/en/stable/>`_-based projects up-to-date.
 
+Install with::
 
+    pip install [email protected]:vorausrobotik/voraus-template-updater.git
 
-A longer description of your project goes here...
+Run with::
 
+    update-template <user or organization>
 
+A GitHub token will be retrieved from the ``GITHUB_TOKEN`` environment variable.
+It can also be passed via the ``--github-access-token`` option.
+
+Find out more by running::
+
+    update-template --help