Improve wording of first example for path-based gesture (#4268)

Under Intent, we currently have:

> A **path-based gesture** involves an interaction where not just the
endpoints matter, but how the pointer moves between these points.
>  
> If the gesture is only recognised if the user moves in a (mostly)
straight line from the start point to the end point, it is an example of
a path-based gesture.

That second sentence is confusing. It is an example of a common
_characteristic_ of some path-based gestures. I propose replacing it
with:

> Swiping is an example of a **path-based gesture** which is only
recognized when the user moves in a (mostly) straight line from the
start point to the end point.

---------

Co-authored-by: Mike Gower <[email protected]>

Author: bruce-usab

understanding/21/pointer-gestures.html

@@ -24,7 +24,7 @@ <h2>Intent of this Success Criterion</h2>
 
 			<p>A <strong>path-based gesture</strong> involves an interaction where not just the endpoints matter, but how the pointer moves between these points.</p>
 
-			<p>If the gesture is only recognised if the user moves in a (mostly) straight line from the start point to the end point, it is an example of a <strong>path-based gesture</strong>.</p>
+			<p>Swiping is an example of a <strong>path-based gesture</strong>, which is only recognized when the user moves in a (mostly) straight line from the start point to the end point.</p>
 
 			<figure id="figure-path-based-gesture-1">
 				<img src="img/path-based-gesture-1.png" width="400" alt="Hand showing a starting touch, 1. Moving in a straight line to a second point, 2." />