Slight wording tweak.

Thanks @TallTed.

Co-authored-by: Ted Thibodeau Jr <[email protected]>

Author: BigBlueHat

playground/index.html

@@ -81,7 +81,7 @@
     <div class="container">
       <h2>JSON-LD Playground</h2>
       <div class="alert alert-success">
-        <strong><a href="next/">Checkout our next Playground!</a></strong>
+        <strong><a href="next/">Check out our next Playground!</a></strong>
       </div>
       <p>
         Play around with JSON-LD markup by typing out some JSON below and