Add lock machines to Pro plan features list on Pricing page

Author: laurakalbag

static/pricing/index.html

@@ -126,6 +126,7 @@ <h2 class="pricing-heading">Professional</h2>
                 <li class="pricing-text">Version history</li>
                 <li class="pricing-text">Import from GitHub</li>
                 <li class="pricing-text">Live simulation mode</li>
+                <li class="pricing-text">Lock machines</li>
                 <li class="pricing-text">Color states and transitions</li>
                 <li class="pricing-text">Priority support</li>
                 <li class="pricing-text">GitHub Sync (coming soon!)</li>