Call dynamic-readme reusable workflow (#1208)

We want to have a way to edit our README footer at one place
and have the changes from there be propagated to our repos.

By adding this snippet in the README, we call this reusable workflow:
https://github.com/thoughtbot/templates/blob/main/.github/workflows/dynamic-readme.yaml
that renders and updates the README footer dynamically.

More details about this approach can be found here:
https://thoughtbot.com/blog/automate-processes-with-reusable-github-workflows

.github/workflows/dynamic-readme.yml

@@ -0,0 +1,19 @@
+name: update-templates
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - README.md
+  workflow_dispatch:
+
+jobs:
+  update-templates:
+    permissions:
+      contents: write
+      pull-requests: write
+      pages: write
+    uses: thoughtbot/templates/.github/workflows/dynamic-readme.yaml@main
+    secrets:
+      token: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -115,18 +115,6 @@ under the terms specified in the [LICENSE] file.
 
 [LICENSE]: /LICENSE
 
-## About
+<!-- START /templates/footer.md -->
 
-Suspenders is maintained by [thoughtbot].
-
-![thoughtbot](https://thoughtbot.com/brand_assets/93:44.svg)
-
-Suspenders is maintained and funded by thoughtbot, inc.
-The names and logos for thoughtbot are trademarks of thoughtbot, inc.
-
-We love open source software!
-See [our other projects][community]
-or [hire us][hire] to help build your product.
-
-[community]: https://thoughtbot.com/community?utm_source=github
-[hire]: https://thoughtbot.com/hire-us?utm_source=github
+<!-- END /templates/footer.md -->