icons on people page should have either ARIA labels or be restructured

[Inkering]

part of a series of accessibility improvements//maintenance taeyoon asked me to work on, I'm going to sort through and make PR's for these where possible

On the grid-based people page, each link section for each person could benefit a text label describing the role of the link icon beyond the url.

sfpc.github.io/_layouts/people.html

Lines 40 to 55 in 0b33442

	</span><span class="links">
	{% if person.twitter %}
	<a href="http://twitter.com/{{ person.twitter }}"><i class="fa fa-twitter"></i></a>
	{% endif %}
	{% if person.github %}
	<a href="http://github.com/{{ person.github }}"><i class="fa fa-github"></i></a>
	{% endif %}
	{% if person.instagram %}
	<a href="http://instagram.com/{{ person.instagram }}"><i class="fa fa-instagram"></i></a>
	{% endif %}
	{% if person.website %}
	<a href="{{ person.website }}"><i class="fa fa-globe"></i></a>
	{% endif %}
	{% if person.email %}
	<a href="mailto:{{ person.email }}"><i class="fa fa-email"></i></a>
	{% endif %}