[FIX] *: enforce 1 newline on files end

Part-of: odoo/documentation#2978

extensions/odoo_theme/layout_templates/changelog.html

@@ -27,4 +27,4 @@
             </div>
         </div>
     </div>
-</section>
+</section>

extensions/odoo_theme/layout_templates/menu.html

@@ -9,4 +9,4 @@
     `collapse_menu` is passed directly to Jinja with sphinx-build's option `-A collapse_menu=True`.
     It it evaluated as a string, so what we're really evaluating here is `collapse_menu != None`.
 #}
-{{ toctree(collapse=collapse_menu, titles_only=True, includehidden=False)}}
+{{ toctree(collapse=collapse_menu, titles_only=True, includehidden=False)}}