Add an option to not display descriptions

.Description is meant to be used for metadata purpose: https://gohugo.io/methods/page/description/

Hugo document has emphasized this in the .Description page:

Conceptually different from a content summary, a page description is typically used in metadata about the page.

Hugo embedded templates are consistent in this regard.

To maintain backward compatibility, add an option showDescription to disable displaying descriptions.

PR Checklist

[ ] This change adds/updates translations and I have used the template present here.
[x] I have enabled maintainer edits for this PR.
[x] I have verified that the code works as described/as intended.
[ ] This change adds a Social Icon which has a permissive license to use it.
[x] This change does not include any CDN resources/links.
[x] This change does not include any unrelated scripts such as bash and python scripts.
[ ] This change updates the overridden internal templates from HUGO's repository.