first pass at adding mathjax

Using the workaround as suggested here:
#515 (comment)

Author: chriddyp

plotly/offline/offline.py

@@ -140,7 +140,20 @@ def init_notebook_mode(connected=False):
             '</script>'
             '').format(script=get_plotlyjs())
 
+    mathjax_script = (
+        '<script>'
+        'var waitForPlotly = setInterval( function() {'
+        '   if( typeof(window.Plotly) !== "undefined" ){'
+        '       MathJax.Hub.Config('
+        '           { SVG: { font: "STIX-Web" }, displayAlign: "center" });'
+        '       MathJax.Hub.Queue(["setRenderer", MathJax.Hub, "SVG"]);'
+        '       clearInterval(waitForPlotly);'
+        '   }}, 250 );'
+        '</script>'
+    )
+
     ipython_display.display(ipython_display.HTML(script_inject))
+    ipython_display.display(ipython_display.HTML(mathjax_script))
     __PLOTLY_OFFLINE_INITIALIZED = True