test: add compact checkbox in test app (jbaysolutions#654)

Author: jledentu

src/App.vue

@@ -32,6 +32,7 @@
             <input type="checkbox" v-model="mirrored"/> Mirrored
             <input type="checkbox" v-model="responsive"/> Responsive
             <input type="checkbox" v-model="preventCollision"/> Prevent Collision
+            <input type="checkbox" v-model="compact"/> Vertical Compact
             <div style="margin-top: 10px;margin-bottom: 10px;">
                 Row Height: <input type="number" v-model="rowHeight"/> Col nums: <input type="number" v-model="colNum"/>
                 Margin x: <input type="number" v-model="marginX"/> Margin y: <input type="number" v-model="marginY"/>