docs: use tip for nugget

docs/examples/emulator/robustgasp/plot_scalargasp.py

@@ -115,7 +115,7 @@ plt.tight_layout()
 
 # %% md
 #
-# Above example shows how to train a GP emulator based on noise-free training data,
+# .. tip:: Above example shows how to train a GP emulator based on noise-free training data,
 #    which is often the case of emulating a deterministic simulator. If you are dealing
 #    with noisy training data, you can
 #