Images are Missing Alt Tags

[alexives]

A bunch of the image tags are missing alt tags on them, not sure if there's a way to make this configurable, but that'd be neat. The result is that a built site with this theme does not pass html-proofer.

_includes/blog-feed.html
7:        <img src="{{post.image}}">

_includes/contact.html
3:    <img class="activator" src="assets/images/contact4.png">

_includes/portfolio_cards.html
5:        <img class="activator" src="../assets/images/desk.jpg">
20:        <img class="activator" src="../assets/images/typewriter.jpg">
38:        <img class="activator" src="../assets/images/contact2.jpg" style="height:366px;">
53:          <img class="activator" src="../assets/images/contact4.png">