docs: add avatar samples

docs/index.html

@@ -76,6 +76,7 @@
                 class="item"
                 v-html="sample.code">
               </div>
+              <p v-if="sample.description" class="description nes-text">{{ sample.description }}</p>
               <p v-if="sample.note" class="note nes-text is-error">{{ sample.note }}</p>
               <button type="button" class="nes-btn is-primary showcode" @click="sample.showCode = !sample.showCode">&lt;&gt;</button>
             </section>