Equations not rendering for the "Permanent vs Persistent Income Shocks" example notebook

[dedwar65]

There's a recently submitted pull request for edits to this notebook: "Permanent vs Persistent Income Shocks". However, at the "hark.readthedocs.io" site, the equations describing the agent's problem under the "General income process model" section of the notebook does not render on the webpage. I am not sure if my edits will correct this, since the equations render just fine in jupyter.