Update pyexcel-index.rst.jj2

.moban.d/docs/source/pyexcel-index.rst.jj2

@@ -8,7 +8,7 @@ manipulate and write data in various excel formats. This library makes
 information processing involving excel files an enjoyable task. The data in
 excel files can be turned into :ref:`array or dict<a-list-of-data-structures>`
 with minimal code and vice versa. This library focuses on data
-processing using excel files as storage media hence fonts, colors and charts
+processing using excel files. Therefore, fonts, colors and charts
 were not and will not be considered.
 
 {% include "origin.rst.jj2" %}