DOC: Rename gallery example for GMT logo (#3856)

Author: yvonnefroehlich

examples/gallery/embellishments/logo.py renamed to examples/gallery/embellishments/gmt_logo.py

@@ -1,8 +1,8 @@
 """
-Logo
-====
+GMT logo
+========
 
-The :meth:`pygmt.Figure.logo` method allows to place the GMT logo on a map.
+The :meth:`pygmt.Figure.logo` method allows to place the GMT logo on a figure.
 """
 
 # %%
@@ -11,9 +11,8 @@
 fig = pygmt.Figure()
 fig.basemap(region=[0, 10, 0, 2], projection="X6c", frame=True)
 
-# Add the GMT logo in the Top Right (TR) corner of the current map,
-# scaled up to be 3 cm wide and offset by 0.3 cm in x direction
-# and 0.6 cm in y direction.
+# Add the GMT logo in the Top Right (TR) corner of the current plot, scaled up to be 3
+# centimeters wide and offset by 0.3 cm in x direction and 0.6 cm in y direction.
 fig.logo(position="jTR+o0.3c/0.6c+w3c")
 
 fig.show()