Update readme (#15)

-clarified two steps in the how-to

Author: ubidefeo

Diff for: README.md

@@ -7,6 +7,7 @@ iot-cloud-cli is a command line interface that allows to exploit the features of
 This is all you need to use iot-cloud-cli for device **provisioning**:
  * A client ID and a secret ID, retrievable from the [cloud](https://create.arduino.cc/iot/integrations) by creating a new API key
  * arduino-cli in daemon mode, to start it use the command 'arduino-cli daemon'
+ * The folder containing the precompiled provisioning firmwares (`binaries`) needs to be in the same location you run the command from
 
 This is all you need to use iot-cloud-cli as a **virtual device**:
  * A "Generic ESP8266 Module" or "Generic ESP32 Module" device in IoT Cloud (requires a Maker plan)
@@ -22,6 +23,14 @@ Once you have the IDs, call this command with your parameters:
 
 `$ iot-cloud-cli config -c <clientID> -s <secretID>`
 
+A file named `config.yaml` will be created in the Current Working Directory containing the login credentials.
+Example
+
+```yaml
+client: 00112233445566778899aabbccddeeff
+secret: 00112233445566778899aabbccddeeffffeeddccbbaa99887766554433221100
+```
+
 ## Device provisioning
 
 When provisioning a device, you can optionally specify the port to which the device is connected to and its fqbn. If they are not given, then the first device found will be provisioned.