Deletion of Pivot chart

Comment: to pivot table. I added a source that is a book chapter on pivot charts; there are other sources, too. While some of that chapter is how-to material, there is plenty of content that supports the basic description of these charts in the article. Merge of verifiable content is preferred over deletion per our policy . Hence, merge. --&#123;&#123;u&#124
Stance: merge
Cited policy: Wikipedia:Deletion policy (WP:ATD)