pdf-merge.py: Fix 'perserving' -> 'preserving' typo in module doctest

diff --git a/posts/PDF_bookmarks_with_Ghostscript/pdf-merge.py b/posts/PDF_bookmarks_with_Ghostscript/pdf-merge.py
index 14a4412b17fa62bb9e87f304957d90762d2e6faa..5c80fe2bdd677d9d3571f482aa0625c7ea612e3d 100755 (executable)
--- a/posts/PDF_bookmarks_with_Ghostscript/pdf-merge.py
+++ b/posts/PDF_bookmarks_with_Ghostscript/pdf-merge.py
@@ -16,7 +16,7 @@
 # License along with this program.  If not, see
 # <http://www.gnu.org/licenses/>.
 
-"""Merge PDFs perserving bookmarks.
+"""Merge PDFs preserving bookmarks.
 
 Thanks to Larry Cai for suggesting that Unicode be supported and for
 discussion about the `--pdfmarks` option.