Re-write web pages (batch 1)

Batch 1 of web pages takes the content from the following pages:

- [ Learning about OpenACRs](https://federalist-6d3494a6-5b03-42fa-82f2-57f3bbb203af.app.cloud.gov/site/gsa/openacr-website/about/)
- [Roadmap](https://federalist-6d3494a6-5b03-42fa-82f2-57f3bbb203af.app.cloud.gov/site/gsa/openacr-website/roadmap/)

... and creates new pages that are better organized with improved content. The new pages are:

- [Why OpenACR](https://docs.google.com/document/d/1SLYSkw7_LjranxhfQgIT6Ksfa6Ns2hKAnphoVEDuUco/edit#heading=h.g93kugf6fkf6)
- [OpenACR initiative](https://docs.google.com/document/d/1Gxss6UtNsDH-xaH1mUvQpkLKxzjNQdvvzW8bJ3StTxk/edit#)

Please refer to the [content audit](https://docs.google.com/spreadsheets/d/1j-0MqSJiTrUy_U1NsYV9DqxlqDRR0T8M1K4-t9dTtFQ/edit#gid=1169823119) to see how these changes reflect the recommendations.

If approved, these changes can be incorporated into the website according to the [new proposed structure](https://app.mural.co/t/civicactions3117/m/civicactions3117/1643640500798/b2396b11d306e100097876a1f00de60391f93f33?sender=u20d1b8757515647ded159751)

Start by comparing the existing Learning about OpenACRs and Roadmap pages with the proposed Why OpenACR and OpenACR initiative documents. Read the content audit and proposed structure to understand the intended organization. Done means the approved content is incorporated into the website as the new pages and reflects those recommendations.

Written by the indexing model from the issue text.