Add author pages

[bluenex]

In case reader want to look for the article written by specified author. I've tested looping through site.data.authors but it doesn't seem to work well.

{% for item_hash in site.data.authors %}
  {% for item in item_hash %}
    <li>{{ item[0] }}</li>
    <li>{{ item[1] }}</li>
  {% endfor %}
{% endfor %}

This doesn't work either.

[bluenex]

we are going to change theme according to #20, the theme includes multiple authors too.