Accessibility Improvement

[tushuhei]

Some screen reader programs read Budou-enabled paragraphs chunk-by-chunk, which makes their reading speed slow. We may want to add capability to configure attributes of each SPAN tag in order to let users put ARIA tags to control a screen reader's behavior.

Here's an example which controls screen reading properly.

<p id="description" aria-label="やりたいことのそばにいる Android">
  <span class="ww" aria-describedby="description">やりたい</span>
  <span class="ww" aria-describedby="description">ことの</span>
  <span class="ww" aria-describedby="description">そばに</span>
  <span class="ww" aria-describedby="description">いる Android</span>
</p>