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 <[email protected]>

README.md

@@ -52,8 +52,8 @@ tools:
 * [Graph Explorer](https://github.com/invanalabs/graph-explorer)
 * [Gremlin-Visualizer](https://github.com/prabushitha/gremlin-visualizer)
 * [G.V() - Gremlin IDE](https://gdotv.com)
+* [Ogma by Linkurious](https://doc.linkurious.com/ogma/latest/tutorials/janusgraph/)
 * [KeyLines by Cambridge Intelligence](https://cambridge-intelligence.com/keylines/janusgraph/)
-* [Linkurious](https://doc.linkurio.us/ogma/latest/tutorials/janusgraph/)
 * [ReGraph by Cambridge Intelligence](https://cambridge-intelligence.com/regraph/)
 * [Tom Sawyer Perspectives](https://www.tomsawyer.com/perspectives/)
 
@@ -107,7 +107,7 @@ tools:
 
     * janusgraph-announce+subscribe (at) lists.lfaidata.foundation
     * janusgraph-announce+unsubscribe (at) lists.lfaidata.foundation
-    
+
 ## Contributing
 
 Please see [`CONTRIBUTING.md`](CONTRIBUTING.md) for more information, including