ExcelWriter not in docs
[Searching for "ExcelWriter"](http://pandas.pydata.org/pandas-docs/stable/search.html?q=excelwriter&check_keywords=yes&area=default) on the documentation doesn't find anything about [`pandas.io.parser.ExcelWriter`](https://github.com/pydata/pandas/blob/master/pandas/io/parsers.py#L2101).

Is this intentional or is it not being scraped correctly?
