Update touch instructions file path

Author: mahoneycm

_includes/sxs/02-extending/part-three.html

@@ -97,7 +97,7 @@ <h3 class="step">Add stylesheet partial.</h3>
     Create a new stylesheet partial for our new component by entering the following in the free terminal window:
   </p>
   <div class="terminal">
-    <pre>touch assets/css/components/_my-testimonial.scss</pre>
+    <pre>touch _theme/components/_my-testimonial.scss</pre>
   </div>
   <p class="step-description">
     And then we'll import this new stylesheet into our USWDS custom styles.

_includes/sxs/02-extending/part-two.html

@@ -40,7 +40,7 @@ <h3 class="step">Create a custom stylesheet for our custom card component.</h3>
     Now let's add our new <strong>my-card</strong> stylesheet. It's standard naming convention to prefix SCSS partials with an underscore (as we've already seen in <strong>_uswds-theme</strong> and <strong>_uswds-theme-custom-styles</strong>).
   </p>
   <div class="terminal">
-    <pre>touch assets/css/components/_my-card.scss</pre>
+    <pre>touch _theme/components/_my-card.scss</pre>
   </div>
 
   <h3 class="step">Import the new stylesheet into USWDS custom styles.</h3>