**Apache Airflow version**: 1.10.11

**Environment**: Python 3.7

- **Cloud provider or hardware configuration**:
- **OS** (e.g. from /etc/os-release): PRETTY_NAME="Debian GNU/Linux 10 (buster)"
 (from python3.7-slim-buster docker image)
- **Kernel** (e.g. `uname -a`): Linux 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 GNU/Linux
- **Install tools**:
- **Others**:

**What happened**:

Using a markdown formatted table does not work.

**What you expected to happen**:

To be able to see a formated table within DAG view

**How to reproduce it**:

Add a tabular formatted code do dag.doc_md.

Example:

> mytable:
> 
> | a | b | c |
> | ------------- | ------------- | ------------- |
> | a | b | c |

[Table not formatted](https://i.imgur.com/l6JXuWe.png)

**Anything else we need to know**: N/A

airflow/www/utils.py
"""<li class="paginate_button {disabled}" id="dags_last">
    <a href="{href_link}" aria-controls="dags" data-dt-idx="3" tabindex="0">&raquo;</a>
</li>"""
    )
    page_node = Markup(
        """<li class="paginate_button {is_active}">
    <a href="{href_link}" aria-controls="dags" data-dt-idx="2" tabindex="0">{page_num}</a>
</li>"""
    )
    output = [Markup('<ul class="pagination" style="margin-top:0;">')]
    is_disabled = 'disabled' if current_page <= 0 else ''
    output.append(
        first_node.format(
            href_link="?{}".format(get_params(page=0, search=search, status=status)),  
            disabled=is_disabled,
        )
    )
    page_link = void_link
    if current_page > 0:
        page_link = '?{}'.format(get_params(page=(current_page - 1), search=search, status=status))
    output.append(previous_node.format(href_link=page_link, disabled=is_disabled))  
    mid = int(window / 2)
    last_page = num_of_pages - 1
    if current_page <= mid or num_of_pages < window:
        pages = list(range(0, min(num_of_pages, window)))
    elif mid < current_page < last_page - mid:
        pages = list(range(current_page - mid, current_page + mid + 1))
    else:
        pages = list(range(num_of_pages - window, last_page + 1))
    def is_current(current, page):