docs: Update installation instructions

Change-Id: Id3639b4ac1110d2f770e89aa9f24d716f49d7b6d
diff --git a/docs/source/cs.rst b/docs/source/cs.rst
index 2940129..d3ae9e8 100644
--- a/docs/source/cs.rst
+++ b/docs/source/cs.rst
@@ -20,8 +20,8 @@
 <https://named-data.net/wp-content/uploads/2016/03/ndn-0021-6-nfd-developer-guide.pdf>`_, section 3.3.
 
 
-To control the maximum size and the policy of NFD's Content Store use :ndnsim:`StackHelper::setCsSize()` and
-:ndnsim:`StackHelper::setPolicy()` methods:
+To control the maximum size and the policy of NFD's Content Store use ``StackHelper::setCsSize()`` and
+``StackHelper::setPolicy()`` methods:
 
       .. code-block:: c++