foundry/Data/systems/dnd5e/templates/items/background.hbs

<form class="{{cssClass}} flexcol" autocomplete="off">

  {{!-- Item Sheet Header --}}
  <header class="sheet-header flexrow">
    <img class="profile" src="{{item.img}}" data-tooltip="{{item.name}}" data-edit="img"/>

    <div class="header-details flexrow">
      <h1 class="charname">
        <input name="name" type="text" value="{{item.name}}" placeholder="{{ localize 'DND5E.BackgroundName' }}"/>
      </h1>

      <div class="item-subtitle">
        <h4 class="item-type">{{itemType}}</h4>
        <span class="item-status">{{itemStatus}}</span>
      </div>

      <ul class="summary flexrow">
        <li>
          <input type="text" name="system.source" value="{{system.source}}" placeholder="{{ localize 'DND5E.Source' }}"/>
        </li>
      </ul>
    </div>
  </header>

  {{!-- Item Sheet Navigation --}}
  <nav class="sheet-navigation tabs" data-group="primary">
      <a class="item active" data-tab="description">{{ localize "DND5E.Description" }}</a>
      <a class="item" data-tab="advancement">{{ localize "DND5E.AdvancementTitle" }}</a>
  </nav>

  {{!-- Item Sheet Body --}}
  <section class="sheet-body">

    {{!-- Description Tab --}}
    <div class="tab flexrow active" data-group="primary" data-tab="description">
      {{editor descriptionHTML target="system.description.value" button=true editable=editable engine="prosemirror"
               collaborate=false}}
    </div>

    {{!-- Advancement Tab --}}
    {{> "dnd5e.item-advancement"}}
  </section>
</form>