Feature/add presentation and exec summary - changed link in the README too (#11)

* Add toolkit overview presentation and executive summary

- Add non-technical presentation explaining the toolkit's capabilities
- Simplify language throughout for non-technical audiences
- Add executive summary one-pager for stakeholders
- Generate HTML slides using Marp for easy viewing
- Add docs:slides npm script to regenerate slides
- Update README with links to overview materials

* Update presentation link and minor content changes

* Simplify README links to presentation

* Add index.html redirect for GitHub Pages

* Fix README link to use GitHub Pages URL

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Co-authored-by: Leo Kacenjar <[email protected]>

Author: mryhmln

README.md

@@ -2,7 +2,7 @@
 
 This toolkit helps teams build consistent, well-documented APIs for safety net programs—enabling faster integration between benefits systems and reducing the technical barriers to improving service delivery.
 
-**New here?** Start with the [Executive Summary](./docs/presentation/executive-summary.md) for a one-page overview, or read the [Toolkit Overview](./docs/presentation/safety-net-openapi-overview.md) for a detailed walkthrough.
+**New here?** Start with the [Executive Summary](./docs/presentation/executive-summary.md) for a one-page overview, or view the [Toolkit Overview](https://codeforamerica.github.io/safety-net-openapi/presentation/safety-net-openapi-overview.html) presentation for a detailed walkthrough.
 
 ## About This Repository