title: Apply styles while exporting to 'xlsx' in pandas with XlsxWriter
body: <p>I use the .to_excel method of pandas to write a DataFrame as an Excel workbook.
  This works nice even for multi-index DataFrames as index cells become merged.
  When using the pure XlsxWriter I can apply formats to cells what also works nice.</p>
  
  <p>However I couldn't find a way to do the same with the pandas method. Just passing a dict with column names and styles would be most intuitive.</p>
  
  <p>Is there any way to do so?</p>