Doc: Update shortcut descriptions

Follow-up commit 27966a17499a23f2d681f4318787eb49c938d6b1.

Task-number: QTCREATORBUG-10170
Change-Id: Ifbb370ee6500e0cfdc63772c05bf33cae4b957c9
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

doc/qtcreator/src/howto/creator-keyboard-shortcuts.qdoc

@@ -729,7 +729,7 @@
             \li
             \li  Alt+S, Alt+D
         \row
-            \li  Diff project
+            \li  Diff project or repository
             \li
             \li
             \li  Alt+G, Alt+Shift+D
@@ -753,7 +753,7 @@
             \li  Alt+P, Alt+F
             \li
         \row
-            \li  Log project
+            \li  Log repository
             \li
             \li
             \li  Alt+G, Alt+K