Mention Draft 3 support

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

Author: jviotti

content/_index.html

@@ -448,7 +448,7 @@ <h4 class="h3 my-0 fw-bold">Free</h4>
           </div>
           <div class="card-body d-flex flex-column p-3 p-md-4">
             <ul class="list-unstyled mt-3 mb-4 flex-grow-1">
-              <li class="mb-3"><i class="bi bi-check-circle-fill text-success me-2"></i>Draft 4, 6, 7, 2019-09 and 2020-12 support</li>
+              <li class="mb-3"><i class="bi bi-check-circle-fill text-success me-2"></i>Draft 3, 4, 6, 7, 2019-09 and 2020-12 support</li>
               <li class="mb-3"><i class="bi bi-check-circle-fill text-success me-2"></i>Custom meta-schema support <i class="bi bi-info-circle text-muted" data-bs-toggle="tooltip" data-bs-title="The registry rejects any schema that does not validate against its meta-schema, whether official or custom. No invalid schemas make it in"></i></li>
               <li class="mb-3"><i class="bi bi-check-circle-fill text-success me-2"></i>Flexible directory structure <i class="bi bi-info-circle text-muted" data-bs-toggle="tooltip" data-bs-title="Organize schemas by team, department, domain, or any hierarchy that fits your organisation. Most alternatives force a flat or rigid structure"></i></li>
               <li class="mb-3"><i class="bi bi-check-circle-fill text-success me-2"></i><a href="https://one.sourcemeta.com/api/">Full HTTP API access</a></li>