v0.7.1 — fix blank native Excel sparklines

Native Excel sparklines rendered blank in real Excel: sparklines ignore hidden rows/columns by default and the series data lives in hidden columns. Every x14:sparklineGroup now sets displayHidden="1" (AUG-29). See CHANGELOG.md.

Install by asset URL:

npm i https://github.com/methodify/augrid/releases/download/v0.7.1/augrid-core-0.7.1.tgz
npm i https://github.com/methodify/augrid/releases/download/v0.7.1/augrid-react-0.7.1.tgz