Retitle some essential buttons

pyleds/templates/index.html

@@ -81,9 +81,9 @@
     <div class="spacer-row"></div>
     <div class="container">
         <div class="row">
-            <button onclick="doInit()">init</button>
+            <button onclick="doInit()">intro</button>
-            <button onclick="doCancel()">end loop</button>
+            <button onclick="doCancel()">halt</button>
-            <button onclick="doBlind()">off</button>
+            <button onclick="doBlind()">leds off</button>
 
             <label><input type="checkbox" id="looping" /><b> loop</b></label>
         </div>