Renamed fiji tool to let automatic tools pick it up

tools.json

@@ -117,7 +117,7 @@
             }
         ]
     },
-    "fiji-container": {
+    "fiji": {
         "short_description": "ImageJ and Fiji for image processing",
         "description": "ImageJ and Fiji with amongst others several electron-microscopy specific plug-ins",
         "image": "gitlab-registry.mpcdf.mpg.de/nomad-lab/nomad-remote-tools-hub/fiji-webtop",
@@ -156,4 +156,4 @@
             }
         ]
     }
-}
\ No newline at end of file
+}