Merge pull request #146 from ghiscoding/feat/charts

feat: add Excel Charts

Author: ghiscoding

docs/TOC.md

@@ -17,6 +17,7 @@
 - [Tables](tables.md)
 - [Theming Tables](theming-tables.md)
 - [Tables Summaries](tables-summaries.md)
-- [Adding Headers and Footers to a Worksheet](worksheet-headers-footers.md)
-- [Inserting images into spreadsheets](inserting-pictures.md)
+- [Adding Headers/Footers to a Worksheet](worksheet-headers-footers.md)
+- [Inserting Images](inserting-pictures.md)
+- [Inserting Charts](inserting-charts.md)
 - [Streaming Export API](streaming.md)