Fix grammar error in CSS content-visibility doc (#2917)

files/en-us/web/css/content-visibility/index.html

@@ -14,7 +14,7 @@
 ---
 <p>{{CSSRef}}</p>
 
-<p><span class="seoSummary">The <strong><code>content-visibility</code></strong> <a href="/en-US/docs/Web/CSS">CSS</a> property controls whether or not an element renders its contents at all, along with forcing a strong set of containments, allowing user agents to potentially omit large swathes of layout and rendering work until it becomes needed.</span> Basically it enables the user agent to skip an element's rendering work, including layout and painting, until it is needed, makes the initial page load much faster.</p>
+<p><span class="seoSummary">The <strong><code>content-visibility</code></strong> <a href="/en-US/docs/Web/CSS">CSS</a> property controls whether or not an element renders its contents at all, along with forcing a strong set of containments, allowing user agents to potentially omit large swathes of layout and rendering work until it becomes needed.</span> Basically it enables the user agent to skip an element's rendering work (including layout and painting) until it is needed — which makes the initial page load much faster.</p>
 
 <h2 id="Syntax">Syntax</h2>