cores: timer: fix documentation formatting

The ReStructured Text used was not properly formatted, resulting in
confusing and broken output.  This corrects the output and lets it
format correctly when using sphinx.

Signed-off-by: Sean Cross <sean@xobs.io>

litex/soc/cores/timer.py

@@ -18,31 +18,34 @@ class Timer(Module, AutoCSR, ModuleDoc):
     Provides a generic Timer core.
 
     The Timer is implemented as a countdown timer that can be used in various modes:
-    - Polling : Returns current countdown value to software.
-    - One-Shot: Loads itself and stops when value reaches 0.
-    - Periodic: (Re-)Loads itself when value reaches 0.
 
-    `en` register allows the user to enable/disable the Timer. When the Timer is enabled, it is
+    - Polling : Returns current countdown value to software
+    - One-Shot: Loads itself and stops when value reaches ``0``
+    - Periodic: (Re-)Loads itself when value reaches ``0``
+
+    ``en`` register allows the user to enable/disable the Timer. When the Timer is enabled, it is
     automatically loaded with the value of `load` register.
 
-    When the Timer reaches 0, it is automatically reloaded with value of `reload` register.
+    When the Timer reaches ``0``, it is automatically reloaded with value of `reload` register.
 
-    The user can latch the current countdown value by writing to `update_value` register, it will
-    update `value` register with current countdown value.
+    The user can latch the current countdown value by writing to ``update_value`` register, it will
+    update ``value`` register with current countdown value.
 
     To use the Timer in One-Shot mode, the user needs to:
-    - Disable the timer.
-    - Set the `load` register to the expected duration.
-    - (Re-)Enable the Timer.
+
+    - Disable the timer
+    - Set the ``load`` register to the expected duration
+    - (Re-)Enable the Timer
 
     To use the Timer in Periodic mode, the user needs to:
-    - Disable the Timer.
-    - Set the `load` register to 0.
-    - Set the `reload` register to the expected period.
-    - Enable the Timer.
+
+    - Disable the Timer
+    - Set the ``load`` register to 0
+    - Set the ``reload`` register to the expected period
+    - Enable the Timer
 
     For both modes, the CPU can be advertised by an IRQ that the duration/period has elapsed. (The
-    CPU can also do software polling with `update_value` and `value` to know the elapsed duration)
+    CPU can also do software polling with ``update_value`` and ``value`` to know the elapsed duration)
     """
     def __init__(self, width=32):
         self._load = CSRStorage(width, description="""Load value when Timer is (re-)enabled.""" +