fix grammar by review

doc/config.rst

@@ -428,10 +428,10 @@ documentation on :ref:`intl` for details.
 
    * Add uid line for each msgids in .pot files.
    * Calculate similarity between new msgids and previously saved old msgids.
-     This calculation take many time.
+     This calculation takes a long time.
 
-   If you need a speed for the calculation, you can use ``python-levenshtein``
-   3rd-party package written in C by using
+   If you want to accelerate the calculation, you can use
+   ``python-levenshtein`` 3rd-party package written in C by using
    :command:`pip install python-levenshtein`.
 
    The default is ``False``.