Add a gallery example for the Figure.timestamp method

examples/gallery/embellishments/timestamp.py

@@ -0,0 +1,21 @@
+"""
+Timestamp
+---------
+The :meth:`pygmt.Figure.timestamp` method can draw the
+GMT timestamp logo on the map/plot. A custom label
+can be added via the ``label`` parameter.
+"""
+
+import pygmt
+
+# Define static format string.
+pygmt.config(FORMAT_TIME_STAMP="2023-03-01T20:45:15")
+
+fig = pygmt.Figure()
+fig.timestamp()
+fig.show()
+
+# Plot the GMT timestamp logo with a custom label.
+fig = pygmt.Figure()
+fig.timestamp(label="Powered by PyGMT")
+fig.show()