DOC: show grouped OPM topomaps in tutorial

Author: PragnyaKhandelwal

examples/visualization/plot_evoked_topomap_opm_grouped.py

@@ -245,6 +245,13 @@
 t_peak = evoked.times[np.argmax(np.std(evoked.copy().pick("meg").data, axis=0))]
 fig = evoked.plot_joint(picks="mag")
 
+# %%
+# Demonstrating grouped OPM topomaps
+# ----------------------------------
+# The UCL OPM auditory dataset has already been loaded above, so this extra
+# figure reuses the same real evoked object without any additional downloads.
+fig = evoked.plot_topomap(times=[t_peak], ch_type="mag")
+
 # %%
 # Visualizing coregistration
 # --------------------------