Add links to compatibility pages

This reverts commit 0226f3a.

Author: jnewbery

_includes/header.html

@@ -24,6 +24,7 @@
             <a class="page-link" href="/en/blog/">Blog</a>
             <a class="page-link" href="/en/newsletters/">Newsletters</a>
             <a class="page-link" href="/workshops/">Workshops</a>
+            <a class="page-link" href="/en/compatibility/">Compatibility</a>
             <a class="page-link" href="https://dashboard.bitcoinops.org/">Dashboard</a>
         </div>
       </nav>

index.md

@@ -13,7 +13,7 @@ technologies.
 
 We provide [workshops][], [documentation][scaling book], [weekly
 newsletters][], [original research][dashboard], [case studies and
-announcements][blog], and help facilitate improved relations between businesses
+announcements][blog], [analysis of Bitcoin software and services][compatibility], and help facilitate improved relations between businesses
 and the open source community.
 
 [Learn more about us][about].
@@ -24,6 +24,7 @@ and the open source community.
 [dashboard]: https://dashboard.bitcoinops.org/
 [blog]: /en/blog/
 [about]: /about
+[compatibility]: /en/compatibility/
 
 <h2>Recent newsletters and blog posts</h2>
 <ul class="post-list">