Create new base.html file and replace base.html for new design

[mlissner]

I think all of our templates inherit from base.html with a tag like:

{% extends "base.html" %}

We can't get very far on the redesign until base.html is replaced with a new template that uses tailwind and components.

I think what we can do to make this transition is to add a waffle to all of the new pages.

Ideally, we could do something like:

{% load waffle_tags %}
{% flag "is_new_design" %}
   {% extends "new_base.html" %}
{% else %}
   {% extends "base.html" %}
{% endif %}

Unfortunately, that won't work because the extends tag has to go first, so what we need to do instead is move it to the view with something like:

def my_view(request):
    is_new_design = waffle.flag_is_active(request, "is_new_design")
    context = {"is_new_design": is_new_design}
    return TemplateResponse(request, "help/alert_help.html", context)

And then in your template, you can do:

{% extends is_new_view|yesno:"new_base.html,base.html" %}

From here: https://stackoverflow.com/a/7817990/64911

Later, when the new view is launched, we remove the flags, and we're good to go.

---

So to complete this ticket:

1. Create new_base.html as a clone of base.html, but using tailwind and components. As an MVP, it should just have blank spaces for the header, navbar, and footer.
2. Apply new_base.html to /components as an MVP.