Update readme

Signed-off-by: Jan Losinski <[email protected]>

Author: janLo

README.md

@@ -1,2 +1,22 @@
-# ArduinoLogging
-Log framework for Arduino supporting levels and handlers.
+# ArduinoSimpleLogging
+
+Simple logging-framework for Arduino supporting levels and handlers.
+
+It provides a static `Logger` instance that has static `Print` instances as members.
+These members are `debug`, `info`, `warning` and `error` and represent preconfigured log targets for the available log levels.
+
+As these are `Print` instances, you can use them as drop-in-replacement for `Serial`.
+For example instead of `Serial.println("Hello")` you just write `Logger.debug.println("Hello")`.
+This will print the String `Hello` to all streams that are configured for `DEBUG`.
+
+To configure a `Print` instance for a log level you simply add it as log handler.
+For example, to log all log messages to `Serial` you need to call:
+```cpp
+Logger.addHandler(Logger.DEBUG, Serial);
+```
+
+Log levels are including.
+That means, that when you configure a handler for a certain level, you'll get everything up to this level.
+The available levels are: `ERROR`, `WARNING`, `INFO`, `DEBUG` with debug the highest level.
+So if you configure your Handler for `DEBUG`, you'll get messages for all levels.
+If you configure for `ERROR`, you'll get only error messages.