DOC: Fix typos before the release of v0.19.0 (#4722)

Author: yvonnefroehlich

examples/gallery/embellishments/pygmtlogo.py

@@ -27,7 +27,7 @@
 
 
 # %%
-# Via the ``color``, ``theme``, ``shape`` parameters the appereance of the logo can be
+# Via the ``color``, ``theme``, ``shape`` parameters the appearance of the logo can be
 # changed.
 
 fig = pygmt.Figure()