Transfer Mission and HIFIS Structure

Transferred the descriptive stuff of HIFIS. Not beautiful but should contain the most important information. Second page/mission needs to be designed and discussed with AS,TH -> #11 (closed)

@frust45 can you please check how to make the link button to mission ("HIFIS MISSION") on the main page less dark? Or use different way to make this part clickable.

Closes #7 (closed)

_layouts/frontpage.html

@@ -32,21 +32,29 @@
             <section>
                 <div class="info-col">
                     <div class="info-box">
-                        <h3><i class="fas fa-user-plus" aria-hidden="true"></i>&nbsp; You & HIFIS</h3>
+                        <a href="{% link index.md %}" class="btn btn-outline-light">
+                            <h3><i class="fas fa-user-plus" aria-hidden="true"></i>&nbsp; You & HIFIS</h3>
+                        </a>
                         <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut
                             labore et dolore magna aliqua.</p>
                     </div>
                     <div class="info-box">
-                        <a href="{{ 'mission/' | relative_url }}" class="btn btn-outline-secondary"><h3><i class="fas fa-atom" aria-hidden="true"></i>&nbsp; HIFIS Mission</h3></a>
+                        <a href="{% link mission/index.md %}" class="btn btn-outline-light">
+                            <h3><i class="fas fa-atom" aria-hidden="true"></i>&nbsp; HIFIS Mission</h3>
+                        </a>
                         <p>Strengthening and developing the ICT competences of the whole Helmholtz Association.</p>
                     </div>
                     <div class="info-box">
-                        <h3><i class="fas fa-globe-europe" aria-hidden="true"></i>&nbsp; HIFIS International</h3>
+                        <a href="{% link index.md %}" class="btn btn-outline-light">
+                            <h3><i class="fas fa-globe-europe" aria-hidden="true"></i>&nbsp; HIFIS International</h3>
+                        </a>
                         <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut
                             labore et dolore magna aliqua.</p>
                     </div>
                     <div class="info-box">
-                        <h3><i class="fas fa-road" aria-hidden="true"></i>&nbsp; Now & tomorrow - The HIFIS Roadmap</h3>
+                        <a href="{% link index.md %}" class="btn btn-outline-light">
+                            <h3><i class="fas fa-road" aria-hidden="true"></i>&nbsp; Now & tomorrow - The HIFIS Roadmap</h3>
+                        </a>
                         <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut
                             labore et dolore magna aliqua.</p>
                     </div>