Fix a typo

gem/guidelns/style_en.u

@@ -14,7 +14,7 @@ at the back of their mind when creating an application:
 !item (!B)Never(!b) start with any unsafe assumptions about internal coherence
      between the individual layers. (!B)Example:(!b) A (!nolink [GEMDOS]) drive can lie
      both on a (!nolink [BIOS]) as well as a MetaDOS device. The mouse normally
-     hangs on the keyoboard chip, but it does not have to (with new
+     hangs on the keyboard chip, but it does not have to (with new
      hardware, keyboard interfaces etc.)
 !item (!B)Always(!b) use the highest possible operating system level for a
      task. (!B)Example:(!b) Though the language to be used could be obtained