appsmith-statistics-app/docs/README.md

Navigation updates

• Added the Units Ordered nav button beneath Units Shipped on every Sales canvas so the new sales dashboard route is reachable from Capacity Planning, Units Ordered, and Units Shipped.
• Each page now hardcodes the highlighted button to appsmith.theme.colors.backgroundColor (what used to be the default background) and keeps the inactive buttons at #ffffff, so the active canvas still renders distinctly without referencing appsmith.page.