Rename Linkurious to Ogma

The company Linkurious has multiple products, but nowadays only their
Ogma library supports JanusGraph (opposed to Linkurious Enterprise).
However, our link already pointed to the Ogma docs, so I just changed
the text for the link.

Signed-off-by: Florian Hockmann <florian.hockmann@gdata.de>

Author: FlorianHockmann

_includes/features.html

@@ -88,7 +88,7 @@
                 <p class="second-title"><i class="fas fa-eye"></i> &nbsp; Visualization
                 </p>
                 <div>
-                    <p class="feature-text">JanusGraph supports variety of visualization tools like <a class="feature-link" href="https://arcadeanalytics.com/usermanual/#arcade-analytics">Arcade Analytics</a>, <a class="feature-link" href="https://cytoscape.org">Cytoscape</a>, <a class="feature-link" href="https://tinkerpop.apache.org/docs/current/reference/#gephi-plugin">Gephi</a> plugin for Apache TinkerPop, <a class="feature-link" href="https://github.com/bricaud/graphexp">Graphexp</a>, <a class="feature-link" href="https://gdotv.com">G.V() - Gremlin IDE</a>, <a class="feature-link" href="https://cambridge-intelligence.com/keylines/janusgraph">Key Lines by Cambridge Intelligence</a>, <a class="feature-link" href="https://doc.linkurio.us/ogma/latest/tutorials/janusgraph">Linkurious</a> and <a class="feature-link" href="https://www.tomsawyer.com/perspectives">Tom Sawyer Perspectives</a>.</p>
+                    <p class="feature-text">JanusGraph supports variety of visualization tools like <a class="feature-link" href="https://arcadeanalytics.com/usermanual/#arcade-analytics">Arcade Analytics</a>, <a class="feature-link" href="https://cytoscape.org">Cytoscape</a>, <a class="feature-link" href="https://tinkerpop.apache.org/docs/current/reference/#gephi-plugin">Gephi</a> plugin for Apache TinkerPop, <a class="feature-link" href="https://github.com/bricaud/graphexp">Graphexp</a>, <a class="feature-link" href="https://gdotv.com">G.V() - Gremlin IDE</a>, <a class="feature-link" href="https://cambridge-intelligence.com/keylines/janusgraph">Key Lines by Cambridge Intelligence</a>, <a class="feature-link" href="https://doc.linkurio.us/ogma/latest/tutorials/janusgraph">Ogma by Linkurious</a> and <a class="feature-link" href="https://www.tomsawyer.com/perspectives">Tom Sawyer Perspectives</a>.</p>
                 </div>
             </div>
         </div>