a minor typo in the code mirror stuff

docs/source/interactive/cm_keyboard.rst

@@ -38,5 +38,5 b' del word after Ctrl-Delete Alt-Delete'
 
 .. note::
 
-     These shorcuts are valid for US keyboards, so some shortcuts can change
-     for non-US keyboards.
  No newline at end of file
+     These shortcuts are valid for US keyboards, so some shortcuts can change
+     for non-US keyboards.