fixing a typo in the page heading

a8c0bdc1 · mrtommyb · Thomas Wiecki · 86815d66 · a8c0bdc1
--- a/doc/extending/scan.txt
+++ b/doc/extending/scan.txt
 .. _scan_internals:

-Developper documentation for Scan
+Developer documentation for Scan
 +++++++++++++++++++++++++++++++++

 Context