The activity class in the nav.html is not being added to the pages with activities

[gbergengruen]

The last update of the press is not generating the correct activity class in the nav.html, allowing the interface to show an icon in the navigation.

This was fixed at some point but now it's not working.

The current nav.html contains li like the following:

<li class="nav__list-item">
        <a class="nav__list-link" data-text-id="txt_p53_g0_t0" href="53_s0.html">HABLAR Y VOLAR</a>
</li>

But if this item is an activity, it should be like this:

<li class="nav__list-item **activity**">
        <a class="nav__list-link" data-text-id="txt_p53_g0_t0" href="53_s0.html">HABLAR Y VOLAR</a>
</li>

[gbergengruen]

This issue came back as the page list is generated differently now. @nicpottier, @elasticsounds, do you think that adding an activity icon and the "to do" or "completed" subtitle makes sense in this new schema?

Example from Cuaderno 5

I don't know the user testing feedback regarding this particular feature, but it seemed that it added value. What do you think?