RST tweak

Author: caternuson

docs/design_guide.rst

@@ -448,18 +448,18 @@ struct.pack
 
 Use `struct.pack_into` instead of `struct.pack`.
 
-Use of MicroPython `const()`
+Use of MicroPython ``const()``
 --------------------------------------------------------------------------------
-The MicroPython `const()` feature, as discussed in `this forum post
+The MicroPython ``const()`` feature, as discussed in `this forum post
 <https://forum.micropython.org/viewtopic.php?t=450>`_, and in `this issue thread
 <https://github.com/micropython/micropython/issues/573>`_, provides some
 optimizations that can be useful on smaller, memory constrained devices. However,
-when using `const()`, keep in mind these general guide lines:
+when using ``const()``, keep in mind these general guide lines:
 
-- Always use via an import, ex: `from micropython import const`
+- Always use via an import, ex: ``from micropython import const``
 - Limit use to global (module level) variables only.
 - If user will not need access to variable, prefix name with a leading
-  underscore, ex: `_SOME_CONST`.
+  underscore, ex: ``_SOME_CONST``.
 
 Sensor properties and units
 --------------------------------------------------------------------------------