44 plain default mobile nav

[yuvilio]

Per discussion in #44, this PR switches the current header navbar nav with a basic starter out of the box mobile nav . It's aims are two fold:

1. Remove dependency on bootstrap navbar and it's setup. Utilizing navbar added more constrictions than benefits (shown below).

2. Give a starter option for a basic responsive nav, solving typical needs (mobile nav expand)

Before:

• The desktop menu did not show submenu elements

• The mobile menu was always open (increasing usage of space) and it too did not show submenu (dropdown elements)

After (with this PR):

• The desktop nav has a default hover state for dropdown submenu elements (courtesy of bootstrap hover dropdown):

• In mobile, the menu starts hidden, and a bars hamburger appears on the top right to toggle it open. If the menu item has a dropdown, it's toggleable with a '+' link

As always, this is just an out of the box default option. Feel free to overwrite, if the design you're working with implies a different approach.

[ccorda]

Left a few notes.

One implementation note is that IMO based on common denominator in sites we build, hamburger nav should only be on mobile (xs). For sm-and-up, menu should be visible. For small, I'm ok if nav drops to its own line like this:

<div class="col-md-4 logo"></div>
<div class="col-md-8 nav"></div>

I'd push back on the JS to rearrange markup for mobile nav. Possible I'm misunderstanding the utility, but I don't think we need it. You can get collapsible nav without resorting to JS.

[yuvilio]

I think the js re-arrange is not a big deal, but it's agreed that it's not a must. Can go redudant nav markup (visible-xs, hidden-xs) route instead.

Note that the hamburger menu is indeed only visible in mobile. In sm and up the menu is fully visibly (per screenshots above).

[ccorda]

Looks good Yuval, :shipit: