%h2(data-mercury='simple')><
  = render_region :header do
    Header
%section.container
  = render_region :content, tag: :article do
    Add content here

%h2#header(data-mercury='simple')><
  = render_region :header do
    Header
%section#content.container
  = render_region :content, tag: :article do
    Add content here

Add ids to default template in install generator
Add ids to default template in install generator