Merge pull request #3 from rgov/patch-1

Use correct package name

Author: tannewt

README.rst

@@ -83,7 +83,7 @@ following command to install:
 
 .. code-block:: shell
 
-    circup install pcf8575
+    circup install adafruit-circuitpython-pcf8575
 
 Or the following command to update an existing version: