Add \exception markup

Doc/lib/libthread.tex

@@ -44,8 +44,8 @@ then the thread exits (but other threads continue to run).
 \end{funcdesc}
 
 \begin{funcdesc}{interrupt_main}{}
-Raise a KeyboardInterrupt in the main thread.  A subthread can use this
-function to interrupt the main thread.
+Raise a \exception{KeyboardInterrupt} exception in the main thread.  A subthread
+can use this function to interrupt the main thread.
 \versionadded{2.3}
 \end{funcdesc}
 

Doc/lib/libtokenize.tex

@@ -47,7 +47,7 @@ An older entry point is retained for backward compatibility:
   call to the function should return one line of input as a string.
   Alternately, \var{readline} may be a callable object that signals
   completion by raising \exception{StopIteration}.
-  \versionchanged[Added StopIteration support]{2.5}
+  \versionchanged[Added \exception{StopIteration} support]{2.5}
 
   The second parameter, \var{tokeneater}, must also be a callable
   object.  It is called once for each token, with five arguments,