[IMP] documentation: legal page design

Prior to this commit, the terms and conditions were displayed in a table
with all the languages and it was not practical for the futur, with many
more languages.

task-3073198

closes odoo/documentation#3058

Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>

extensions/odoo_theme/layout.html

@@ -108,6 +108,8 @@
             {%- if pagename == master_doc %}
                 {# Custom landing page on the root of the documentation #}
                 {%- include "layout_templates/homepage.html" %}
+            {%- elif pagename == 'legal' %}
+                {%- include "layout_templates/legal.html" %}
             {%- else %}
                 <article id="o_content" class="doc-body">
                     <div role="main"> {# Beacon used by the Sphinx search to know where to look for a string #}