Remove references to hardware module, change to machine.

Hardware-API.md

@@ -63,13 +63,13 @@ In the method specs below, *NOHEAP* means the function cannot allocate on the he
 - In case that the peripheral is not available (invalid id) ??
 - Operations on non-initialized peripherals ??
 
-# New hardware module
+# New machine module
 
-The classes to control the peripherals of the board will reside in a new module called `hardware`, therefore, by doing:
+The classes to control the peripherals of the board will reside in a new module called `machine`, therefore, by doing:
 
 ```python
-import hardware
-dir(hardware)
+import machine
+dir(machine)
 ```
 
 one can easily see what's supported on the board.