add erb for html-mode

add erb for html-mode

```
1. %
  name: <%= %>
  key: %
  1.1 %rd
    name: <%= render 'form' %>
    key: %rd
2. %e
  name: <% @post.each do |post| %>
  key: %e
3. %t
  name: <%= f.label f.text_field %>
  key: %t   
4. %a
  name: <%= f.label f.text_area %>
  key: %a
5. %lk and %lkdl
  name: <%= link_to 'new post',new_post_path %>
  key: %lk

  name:  <%= link_to 'Destroy', controller_path(controller),
    method: :delete, data: {confirm:'Are you sure?'} %>
  key: %lkdl

  5.1 add to <p>5</p>
  5.2 add to <td>5</td>

6. %err
  name: <%= if @post.errors.any? %>
  key: %err
7. %f
  name: <%= form_for %>
  key: %f
8. p%
  name: <p> <strong>Title:</strong></p>
  key: p%

  8.1 add text_area  
  8.2 add text_field