app/views/devise/mailer/reset_password_instructions.html.erb
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html charset=UTF-8">
</head>
<body>
<% if @resource.name.present? %>
<p>Hello <%= @resource.name %>!</p>
<% else %>
<p>Hello!</p>
<% end %>
<p>Please click the link below and follow the instructions. We'll have you up and running with a new password in no time.</p>
<p><%= link_to "Reset password", edit_password_url(@resource, reset_password_token: @token) %></p>
<p>Didn't request this email? Then you can safely ignore it.</p>
</body>
</html>