[IMP] theme_orchid: update the theme

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

task-2619127

X-original-commit: 40e8281717
Part-of: odoo/design-themes#501

theme_orchid/static/description/index.html

@@ -7,7 +7,7 @@
     first projects on the web. Just drag & drop the new building blocks
     you need to easily build your layout. All layouts are made of sections,
     that you can easily combine to fit your specific project.</p>
-    <img src="orchid_description.png" class="img-fluid d-block mx-auto"/>
+    <img src="orchid_description.jpg" class="img-fluid d-block mx-auto"/>
     <hr/>
 
     <h2 class="text-muted">Orchid Customization Tool</h2>