Clarify that the MathJax comment is Notebook specific.

IPython/core/magics/display.py

@@ -40,7 +40,9 b' class DisplayMagics(Magics):'
     def latex(self, line, cell):
         """Render the cell as a block of latex
         
-        This magic only renders the subset of latex defined by MathJax 
+        The subset of latex which is support depends on the implementation in
+        the client.  In the Jupyter Notebook, this magic only renders the subset 
+        of latex defined by MathJax 
         [here](https://docs.mathjax.org/en/v2.5-latest/tex.html)."""
         display(Latex(cell))