Added icons, helperfunction and new fancy notice message

Added icons from webcrunch resp. heroicons
Added helperfunction to display inline svg with the plugin inline-svg
Implemented fancy notice message webcrunch. Realy nice but does only
work with javascript on.

app/assets/images/icons/outline/envelope.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" aria-hidden="true">
+  <path stroke-linecap="round" stroke-linejoin="round" d="M21.75 6.75v10.5a2.25 2.25 0 01-2.25 2.25h-15a2.25 2.25 0 01-2.25-2.25V6.75m19.5 0A2.25 2.25 0 0019.5 4.5h-15a2.25 2.25 0 00-2.25 2.25m19.5 0v.243a2.25 2.25 0 01-1.07 1.916l-7.5 4.615a2.25 2.25 0 01-2.36 0L3.32 8.91a2.25 2.25 0 01-1.07-1.916V6.75"/>
+</svg>