fix building of docs (no idea why it failed)

Author: dkrenn

src/sage/combinat/k_regular_sequence.py

@@ -61,7 +61,7 @@
 
 .. SEEALSO::
 
-    :doc:`sage/combinat/recognizable_series`,
+    :mod:`recognizable series <sage.combinat.recognizable_series>`,
     :doc:`sage/rings/cfinite_sequence`,
     :doc:`sage/combinat/binary_recurrence_sequences`.
 

src/sage/combinat/recognizable_series.py

@@ -40,7 +40,7 @@
 
 .. SEEALSO::
 
-    :doc:`sage/combinat/k_regular_sequence`,
+    :mod:`k-regular sequence <sage.combinat.k_regular_sequence>`,
     :doc:`sage/rings/cfinite_sequence`,
     :doc:`sage/combinat/binary_recurrence_sequences`.