fix issue with linebroken {doc} (#141)

* test behaviour of {doc}

* alter {doc} linebreak

Author: jbrightuniverse

lectures/dynamic_programming/ifp.md

@@ -34,8 +34,8 @@ This is an essential sub-problem for many representative macroeconomic models
 * {cite}`Huggett1993`
 * etc.
 
-It is related to the decision problem in the {doc}`stochastic optimal growth
-model <../dynamic_programming/optgrowth>` and yet differs in important ways.
+It is related to the decision problem in the {doc}`stochastic optimal growth model <../dynamic_programming/optgrowth>` 
+and yet differs in important ways.
 
 For example, the choice problem for the agent includes an additive income term that leads to an occasionally binding constraint.