Heatmap: start to add basic layout!

pages/prototypes/heatmap.vue

+<template>
+  <Heatmap />
+</template>
+
+<script>
+import Heatmap from '~/web-components-submodule/components/common/Visualisations/Heatmap/Heatmap.vue'
+export default {
+  components: {
+    Heatmap,
+  },
+}
+</script>
+
+<style scoped lang="scss"></style>

web-components-submodule @ 203e41ec

-Subproject commit a9a7251c4c9d820e67ae3739b853a6ba4e9bc40b
+Subproject commit 203e41ecf98b13c6c2cb0d8695405d71477c4ffc