Remove old timer class

Hardware-API.md

@@ -324,21 +324,6 @@ Methods:
 - `apin()` fast method to read the value of the pin.
 - `apin.readtimed(buf, timer)`
 
-## The Timer class
-
-Constructor:
-
-`timer = Timer(id, *, freq, ...)`
-
-Methods:
-
-- `timer.source_freq()` NOHEAP; get the source frequency of the clock (needed?)
-- `timer.counter([counter])` NOHEAP; get/set the timer counter
-- `timer.freq([freq])` NOHEAP*; get/set frequency in Hz (may be a floating point number)
-- `timer.prescaler([prescaler])` NOHEAP; get/set the prescaler
-- `timer.period([period])` NOHEAP; get/set the period
-
-There will probably also need to be timer channels, which can be attached to pins and used for PWM etc.
 
 ## The RTC (Real Time Clock) class