new cluster tutorial

docs/tutorials/tut02_cluster.rst

@@ -87,7 +87,7 @@ The selection we made is not satisfactory as both the toxins and the ribosomes a
 The new umap shows new structure. If we select the rather densely populated area on the left, we have identified the cluster that exclusively represents the toxin cluster. To select the ribosome cluster, we lasso the tip of the larger and fuzzier area by holding :kbd:`Shift` while outlining the area.
 
 .. figure:: ../img/tutorial_2/cluster_refine_05.png
-    :width: 300
+    :width: 650
     :align: center
 
     In the recalculated UMAP we can now separate the toxin from the ribosome cluster.