add end of file, remove alt (first time I see it being used, not sure how useful it is)

Author: honzajavorek

docs/_templates/page.html

@@ -18,5 +18,4 @@
     <meta property="og:image" content="{{ pathto('_static/images/og-image.png', 1) }}">
   {%- endif -%}
   <meta property="og:image:type" content="image/png">
-  <meta property="og:image:alt" content="Ilustrace organizátora Python akcí">
-{%- endblock -%}
+{%- endblock -%}