docs: link to package readmes from root readme (#11531)

## Summary

Link to the READMEs of the packages in the monorepo's root README.

readme.md

@@ -1,6 +1,12 @@
 # Calcite Design System
 
-This is a monorepo containing Calcite Design System packages. Please see the package-specific readmes for more information.
+This is a monorepo containing [Calcite Design System](https://developers.arcgis.com/calcite-design-system/) packages. Please see the package-specific READMEs for more information:
+
+- [`@esri/calcite-components`](./packages/calcite-components/readme.md)
+- [`@esri/calcite-components-react`](./packages/calcite-components-react/README.md)
+- [`@esri/calcite-design-tokens`](./packages/calcite-design-tokens/README.md)
+- [`@esri/calcite-ui-icons`](./packages/calcite-ui-icons/README.md)
+- [`@esri/eslint-plugin-calcite-components`](./packages/eslint-plugin-calcite-components/README.md)
 
 ## Contributing