app/views/devise/mailer/reset_password_instructions.html.erb
<div class="email">
<%= image_tag("logo.png", id: "logo", height: "200px", width: "auto") %>
<p>Hello <%= @resource.email %>!</p>
<p>Someone has requested a link to change your password. You can do this through the link below.</p>
<p><%= link_to 'Change my password', edit_password_url(@resource, reset_password_token: @token) %></p>
<p>If you didn't request this, please ignore this email.</p>
<p>Your password won't change until you access the link above and create a new one.</p>
</div>