static: remove source page

There are not that many repositories so an index is not helpful.

static/index.html

@@ -60,8 +60,9 @@
                     <h2 class="start"><a href="#about">About</a></h2>
 
                     <p>Hakurei is a security-focused Linux container runtime for running unmodified
-                    desktop applications, developed as a non-profit <a href="/source.html">open source
-                    </a> project. It also implements <a href="/package.html">planterette</a>, an
+                    desktop applications, developed as a non-profit <a
+                    href="https://git.gensokyo.uk/security/hakurei" target="_blank">open source</a>
+                    project. It also implements <a href="/package.html">planterette</a>, an
                     experimental self-contained Android-like package manager with modern security
                     features.</p>