title: vuetify : no documentation for v-data-table-header component?
body: <p>Does anyone know how to exactly use <code>&lt;v-data-table-header&gt;</code> in vuetify? <br>
  In v-data-table, there seems to be api documentation for <code>v-data-footer</code> and <code>v-edit-dialog</code> but I can't find anything on <code>v-data-table-header</code></p>