Update README to document minimal console
# Console
-There are two versions of this library;
- * full - contains actual implemetation
- * stub - has stubs for the API
+There are three versions of this library;
+ * minimal - contains an implementation which allows for output, optional
+ input, supports UART and RTT, and has support for `newtmgr` protocol.
+ * full - contains all minimal features and adds formatted output through
+ `console_printf`, console editing and BLE monitor.
+ * stub - has stubs for the API.
You can write a package which uses ```console_printf()```, and builder of a
project can select which one they'll use.
For the package, list in the pkg.yml console as the required capability.
Project builder will then include either sys/console/full or
-sys/console/stub as their choice.
+sys/console/minimal or sys/console/stub as their choice.
