[site/contribute][m]: create basic contribute page and link from nav.

site/config/navLinks.js

@@ -2,6 +2,7 @@ const navLinks = [
   { href: '/about', name: 'About' },
   { href: '/library', name: 'Library' },
   { href: '/claims', name: 'Claims' },
+  { href: '/contribute', name: 'Contribute' },
 ]
 
 export default navLinks

site/pages/contribute.md

@@ -0,0 +1,20 @@
+# Get Involved
+
+This is an open collaborative project. We already have a variety of partners and contributors and we'd love to have more! Here are some of the ways you can get involved:
+
+* Contribute to the [library][], for example by adding articles and research on web3 and background topics.
+* Write up key concepts and ideas. You can check out our [existing list][concepts] to see which ones could be extended or improved.
+* Proof edit articles and transcribe dialogs. Please [get in touch][contact] to find out more.
+* Share the work with others.
+
+We’d also love to have feedback through [our forum][forum]. For example:
+
+* Are there particular topics or areas you think we should cover?
+* Do you disagree with any of our assessments? Have we missed or misunderstood something?
+* Do you have feedback on how we structure or present the thinking?
+
+[library]: /library
+[contact]: /contact
+[concepts]: /concepts
+[forum]: https://github.com/life-itself/web3/discussions
+