Add roadmap section to the README (#7038)

# Pull Request

## 📖 Description

Per the communities request, we have included a link in the root README.md file to the roadmap of FAST Architecture. This roadmap is subject to change and updates and so will be kept updated in the GitHub project.

## ✅ Checklist

### General

<!--- Review the list and put an x in the boxes that apply. -->

- [ ] I have included a change request file using `$ npm run change`
- [ ] I have added tests for my changes.
- [ ] I have tested my changes.
- [x] I have updated the project documentation to reflect my changes.
- [x] I have read the [CONTRIBUTING](https://github.com/microsoft/fast/blob/master/CONTRIBUTING.md) documentation and followed the [standards](https://github.com/microsoft/fast/blob/master/CODE_OF_CONDUCT.md#our-standards) for this project.

README.md

@@ -62,6 +62,10 @@ We hope you're excited by the possibilities that FAST presents. But, you may be
 * "I want to look at a quick reference."
   * [Jump to the Cheat Sheet](https://fast.design/docs/resources/cheat-sheet)
 
+## Roadmap
+
+Major features for the FAST project can be found in the [roadmap](https://github.com/orgs/microsoft/projects/240/views/1).
+
 ## Joining the Community
 
 Looking to get answers to questions or engage with us in realtime? Our community is most active [on Discord](https://discord.gg/FcSNfg4). Submit requests and issues on [GitHub](https://github.com/Microsoft/fast/issues/new/choose), or join us by contributing on [some good first issues via GitHub](https://github.com/Microsoft/fast/labels/community:good-first-issue).