document to use MathJax

Author: archmoj

README.md

@@ -139,6 +139,30 @@ Official plotly.js documentation is hosted at [https://plotly.com/javascript](ht
 These pages are generated by the Plotly [graphing-library-docs repo](https://github.com/plotly/graphing-library-docs) built with [Jekyll](https://jekyllrb.com/) and publicly hosted on GitHub Pages.
 For more info about contributing to Plotly documentation, please read through [contributing guidelines](https://github.com/plotly/graphing-library-docs/blob/master/README.md).
 
+### To support MathJax
+
+*Before* the plotly.js script tag, add:
+
+```html
+<script src="mathjax/MathJax.js?config=TeX-AMS-MML_SVG"></script>
+```
+
+You can get the relevant MathJax files from the internet e.g.
+"https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js?config=TeX-AMS-MML_SVG.js"
+
+By default, plotly.js will modify the global MathJax configuration on load.
+This can lead to undesirable behavior if plotly.js is loaded alongside
+other libraries that also rely on MathJax. To disable this global configuration
+process, set the `MathJaxConfig` property to `'local'` in the `window.PlotlyConfig`
+object.  This property must be set before the plotly.js script tag, for example:
+
+```html
+<script>
+   window.PlotlyConfig = {MathJaxConfig: 'local'}
+</script>
+<script src="plotly.min.js"></script>
+```
+
 ---
 ## Contributing