claudetool: remove knowledge base, focus on about sketch

We should have a more general kb.
Meanwhile, this is important and standalone.
Make it all clearer and sharper.
diff --git a/experiment/experiment.go b/experiment/experiment.go
index a038f60..4c6e530 100644
--- a/experiment/experiment.go
+++ b/experiment/experiment.go
@@ -36,7 +36,7 @@
 
 		{
 			Name:        "kb",
-			Description: "Enable knowledge_base tool",
+			Description: "Enable about_sketch tool",
 		},
 	}
 	byName = map[string]*Experiment{}