Merge pull request #168 from oddbird/sponsor-link-readme

Add OSS sponsorship link to README

README.md

@@ -43,3 +43,18 @@ You can preview the production build with `yarn preview`.
 The staging site is automatically deployed via Netlify to
 <https://www.oddcontrast.com/> every time a commit is made on the `main`
 branch.
+
+---
+
+## Sponsor OddBird's OSS Work
+
+At OddBird, we love contributing to the languages & tools developers rely on.
+We're currently working on polyfills
+for new Popover & Anchor Positioning functionality,
+as well as CSS specifications for functions, mixins, and responsive typography.
+Help us keep this work sustainable
+and centered on your needs as a developer!
+We display sponsor logos and avatars
+on our [website](https://www.oddbird.net/oddcontrast/#open-source-sponsors).
+
+[Sponsor OddBird's OSS Work](https://opencollective.com/oddbird-open-source)