UG: update wording of UG (#2440)

Wording might mislead readers into thinking that PageNavs
cannot be used in normal pages.

Updating the wording will allow readers to know that
individual pages can also use PageNavs.

Let's update the wording to be clearer and more explicit.

Co-authored-by: david <71922282+itsyme@users.noreply.github.com>

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Co-authored-by: david <71922282+itsyme@users.noreply.github.com>

docs/userGuide/syntax/pageNavigationMenus.md

@@ -4,7 +4,7 @@
 
 <div id="content">
 
-**A _Page Navigation Menu_ (==_pageNav_ for short==)  a list of the current page's headings.** Page navigation menus are only available for use in [layouts]({{baseUrl}}/userGuide/tweakingThePageStructure.html#layouts).
+**A _Page Navigation Menu_ (==_pageNav_ for short==) displays a list of the current page's headings.** Page navigation menus are typically configured in [layouts]({{baseUrl}}/userGuide/tweakingThePageStructure.html#layouts), but can also be utilized in individual pages.
 
 ****Adding a pageNav****