add live pressure sensor data

cmd/ingestd/web/index.html

@@ -49,6 +49,10 @@
             <div class="label">Humidity</div>
             <div class="value" id="live-rh">--</div>
           </div>
+          <div class="metric">
+            <div class="label">Pressure hPa</div>
+            <div class="value" id="live-pressure">--</div>
+          </div>
           <div class="metric">
             <div class="label">Wind m/s</div>
             <div class="value" id="live-wind">--</div>