RE: Doc: fix a description regarding WAL summarizer on glossary page

>> While searching the definition of auxiliary processes, I noticed that
>> the description of the WAL summarizer is incorrect. Additionally, I
>> think it's better to add a description for the WAL writer similar to
>> other Auxiliary processes. What do you think?
>
> Good catch.  Would you like to attach a patch?

Thanks for your response. Please take a look at the attached patch.
I've confirmed that it passes all tests.

Regards,
--
Masahiro Ikeda
NTT DATA CORPORATION