Adicionar em `fig` os elementos `label` e `caption`

[robertatakenaka]

Descrição da tarefa

Adicionar em fig os elementos label e caption.
No HTML, o label e o caption de figuras ficam após a imagem.

<fig id="f8" orientation="portrait" position="float">
 <label>FIG. 8.</label>
 <caption>
  <title>Time difference between events F and A as a function of the 
   length of entering plug for bifurcations B to BXXX, where X stands 
   for 0 or 1.</title>
 </caption>
 <graphic xlink:href="f8.jpg"/>
</fig>

https://jats.nlm.nih.gov/publishing/tag-library/1.3/element/fig.html