[IMP] theme_bookstore: update the theme

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

task-2557935

X-original-commit: 1f632d8dd7
Part-of: odoo/design-themes#501

theme_bookstore/views/snippets/s_banner.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+
+<template id="s_banner" inherit_id="website.s_banner">
+    <!-- Filter -->
+    <xpath expr="//div[hasclass('container')]" position="before">
+        <div class="o_we_bg_filter bg-white-75"/>
+    </xpath>
+    <!-- Jumbotron -->
+    <xpath expr="//div[hasclass('jumbotron')]" position="attributes">
+        <attribute name="class" remove="o_cc o_cc1" separator=" "/>
+    </xpath>
+    <!-- Title -->
+    <xpath expr="//h1" position="replace" mode="inner">
+        The best sellers <br/>of the year
+    </xpath>
+    <!-- Button -->
+    <xpath expr="//a[hasclass('btn')]/t" position="replace" mode="inner">
+        Discover it
+    </xpath>
+</template>
+
+</odoo>