docs/website: add SMC-Gateway as a bronze sponsor

SMC Gateway creates applications to enable communications simpler.

They produce an intelligent hub that connects radio networks with
various external systems.

We thanks them for contributing to the LTS maintenance as a bronze
sponsor.

[1] https://smc-gateway.com/
[2] https://www.linkedin.com/company/smc-gateway-ltd

Signed-off-by: Thomas Perale <thomas.perale@mind.be>
Signed-off-by: Julien Olivain <ju.o@free.fr>

docs/website/sponsors.html

@@ -71,6 +71,26 @@
       </div>
     </div>
 
+    <div class="panel-body">
+      <h3>Bronze Sponsors</h3>
+      <div class="sponsors-container">
+        <div class="sponsor-entry">
+          <div class="panel panel-default panel-lts-sponsor">
+            <div class="panel-body">
+              <div class="sponsor-title">
+                <a href="https://smc-gateway.com/">
+                  <img class="img-responsive center-block" style="height: 100%;" src="images/smc-gateway-logo.png"/>
+                </a>
+              </div>
+              <div class="sponsor-body">
+                <a href="https://smc-gateway.com/">SMC Gateway</a>
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+
     <div class="panel panel-primary">
     <div class="panel-heading">Current sponsors</div>
     <div class="panel-body">