Focus on Haskell benefits in main (sub)headline (#337)

Author: malteneuss

site/index.html

@@ -14,7 +14,7 @@
                <br class="hidden-xs alternative-logo-hidden">
                <img src="/img/haskell-logo.svg" alt="Haskell" class="img-responsive alternative-logo-hidden">
                <img src="/img/haskell-uwu.png" alt="Haskell UwU" class="alternative-logo alternative-logo-visible">
-               <h4 class="summary">An advanced, purely functional programming language</h4>
+               <h4 class="summary">Enjoy long-term maintainable software you can rely on</h4>
             </div>
          </div>
          <div class=" span6 col-md-6">