[IMP] theme_zap: update the theme

This commit updates the theme to improve the design with new colors, new
pictures and new snippet customizations.

task-2545207

Part-of: odoo/design-themes#500

theme_zap/views/snippets/s_cover.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+
+<template id="s_cover" inherit_id="website.s_cover">
+    <!-- Section -->
+    <xpath expr="//section" position="attributes">
+        <attribute name="class" add="o_full_screen_height" separator=" "/>
+    </xpath>
+</template>
+
+</odoo>