Rendering problem of documentations

[haojin2]

Description

Some documentation contents are not rendered correctly on the API doc site, for example:
https://mxnet.incubator.apache.org/api/python/ndarray/ndarray.html#mxnet.ndarray.Correlation
https://github.com/apache/incubator-mxnet/blob/master/src/operator/correlation.cc#L178
The math equation for correlation operation is not rendered correctly on the webpage.
Suggest label: Doc

[imsheridan]

I assume this issue was fixed by #10362 and merged already.