Add Terms of Service and tighten mobile public polish.

Route Cookie Preferences to /terms/, link analytics banner there, teal mobile nav, and give the contact form more side padding on small screens.

site/public/views.py

@@ -35,6 +35,10 @@ def about(request):
     return render(request, "public/about.html")
 
 
+def terms(request):
+    return render(request, "public/terms.html")
+
+
 @require_GET
 def robots_txt(request):
     site = _public_site_base(request)
@@ -60,6 +64,7 @@ def sitemap_xml(request):
         ("public:home", "1.0", "weekly"),
         ("public:about", "0.8", "monthly"),
         ("public:contact", "0.9", "monthly"),
+        ("public:terms", "0.5", "yearly"),
     ]
     urls = []
     for name, priority, changefreq in paths: