How to display array key and value

Hi, I have an array in my config.site yaml like so:

mobile_nav:
  'Our School': /our-school
  'Our Community': /our-community
  Gallery: /gallery
  Contact: /contact

How do I get the key and value? I tried this:

{% for item in site.mobile_nav %}
  <li><a href="">{{ key }} {{ value }}</a></li>
{% endfor %}

But it doesn't display either. If I put this it displays the value only:

{% for item in site.mobile_nav %}
  <li><a href="">{{ item }}</a></li>
{% endfor %}

I also tried:

{% for array in site.mobile_nav %}
  <li><a href="">{{ key }} {{ value }}</a></li>
{% endfor %}

And also these inside the loop {{ array.key }} {{ item.key }} etc but nope.

What am I doing wrong?

Also as a side note, Grav add's inverted comma's arround the ones that have 2 words and no '' around the ones with single words.

Thanks

See the Twig documentation on the matter.