Change property to declare pluggable discoveries

Author: silvanocerza

docs/platform-specification.md

@@ -467,14 +467,16 @@ will be used to identify a board by the discovery process when plugged in.
 
 For example we could declare a series of `upload_port.vid` and `upload_port.pid` for the Uno like so:
 
-    uno.upload_port.vid.0=0x2341
-    uno.upload_port.pid.0=0x0043
-    uno.upload_port.vid.1=0x2341
-    uno.upload_port.pid.1=0x0001
-    uno.upload_port.vid.2=0x2A03
-    uno.upload_port.pid.2=0x0043
-    uno.upload_port.vid.3=0x2341
-    uno.upload_port.pid.3=0x0243
+```
+uno.upload_port.vid.0=0x2341
+uno.upload_port.pid.0=0x0043
+uno.upload_port.vid.1=0x2341
+uno.upload_port.pid.1=0x0001
+uno.upload_port.vid.2=0x2A03
+uno.upload_port.pid.2=0x0043
+uno.upload_port.vid.3=0x2341
+uno.upload_port.pid.3=0x0243
+```
 
 In this case we're using the board's `vid` and `pid` to identify it but `upload_port.*` properties can be anything that
 can help identify a certain board. For more detailed information see the