Add that other blog post (#132)

This one's about the rust port.

Author: faho

docs/blog/index.html

@@ -28,6 +28,11 @@ <h3 class="post_title">fish shell blog</h3>
   <div class="post_date"></div>
 
   <div class="post_body"><ul class="post_list"><li>
+        <a href="/blog/rustport/">Fish 4.0: The Fish Of Theseus</a>
+      </li>
+      <p>About two years ago, our head maintainer @ridiculousfish opened what quickly became our most-read pull request:</p>
+<a href="/blog/rustport/">Read more</a>
+      <hr /><li>
         <a href="/blog/fish-4b/">fish-shell 4.0b1, now in Rust</a>
       </li>
       <p>fish is a smart and user-friendly command line shell with clever features that just work, without needing an advanced degree in bash scriptology. Today we are announcing an open beta, inviting all users to try out the upcoming 4.0 release.</p>