[fix] add missing result.length and result.author to simple theme

Closes: https://github.com/searxng/searxng/issues/1027
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/static/themes/simple/src/less/style.less

@@ -260,7 +260,9 @@ article[data-vim-selected].category-social {
     }
   }
 
-  .published_date {
+  .published_date,
+  .result_length,
+  .result_author {
     font-size: 0.8em;
     color: var(--color-result-publishdate-font);
   }

searx/templates/simple/macros.html

@@ -32,8 +32,10 @@
 
 <!-- Draw result sub header -->
 {%- macro result_sub_header(result) -%}
-  {% if result.publishedDate %}<time class="published_date" datetime="{{ result.pubdate }}" >{{ result.publishedDate }}</time>{% endif %}
-  {%- if result.metadata %} <div class="highlight">{{ result.metadata|safe }}</div>{% endif -%}
+  {%- if result.publishedDate %}<time class="published_date" datetime="{{ result.pubdate }}" >{{ result.publishedDate }}</time>{% endif -%}
+  {%- if result.length %}<div class="result_length">{{ _('Length') }}: {{ result.length }}</div>{% endif -%}
+  {%- if result.author %}<div class="result_author">{{ _('Author') }}: {{ result.author }}</div>{% endif -%}
+  {%- if result.metadata %}<div class="highlight">{{ result.metadata|safe }}</div>{% endif -%}
 {%- endmacro -%}
 
 <!-- Draw result sub footer -->