WIP: split hexes and building structure into different layers

public/assets/images/scenario_template.svg

@@ -47,9 +47,9 @@
     <image id="counter-grenade" href="counter_grenade.jpg" width="10"/>
   </defs>
 
-  <g class="gameboard">
+  <g class="gameboard" data-view-elevation="0">
     <rect id="background"/>
-
+    <g class="buildings"/>
     <rect id="dots" fill="url(#asterisk)"/>
 
     <g id="firing-arcs">
@@ -57,6 +57,6 @@
       <g id="lines"/>
     </g>
 
-    <g class="grid" data-view-elevation="0"/>
+    <g class="grid"/>
   </g>
 </svg>