A directive that define a focus Section
<div v-focus-section>
<div v-focus>
<div></div>
</div>
<div v-focus>
<div></div>
</div>
</div>
<!-- section id -->
<div v-focus-section:my-section>
<div v-focus></div>
</div>
<!-- set configuration -->
<div v-focus-section:my-section="{enterTo:'last-focused'}">
<div v-focus></div>
</div>
<!-- set default section -->
<div v-focus-section:my-section.default="{enterTo:'last-focused'}">
<div v-focus></div>
</div>