Theme development

I would like to add classes directly to the a element for the "Add child page" and "Printer-friendly version" links in the Book module that comes with Drupal 8.

In drupal 8 when creating a view for taxonomy terms and add a field I enabled

Link to the Taxonomy term

option. The pathauto module is enabled so it gives following link:

<a href="/site/taxonomy/taxonomy-term" hreflang="en">Taxonomy Term</a>

But I want something like this:

<a href="/site/taxonomy/taxonomy-term" hreflang="en">Read More</a>

In the first look, the process of solving this problem maybe seems very easy, but this problem makes me very confused.

Imagine that I want to have two main-menu one in the header (primary menu/ top bar) and another in the footer region of my site with different style and template.

I follow up below article to add block region as the id of main-menu and make block's template name suggestion unique and dedicated for next customization.

I have view for taxonomy and it has default name field duplicated, one with link and the other without link.

I have changed the one without link by creating views-view-field--myviewname--name.html.twig template file and it is ok.

I want to use a looping functionality in region.html.twig file so I can
wrap elements that outputted from {{ content }} section.

Defult region.html.twig

{% if content %}
  <div class="Parent">
    {{ content }}
  </div>
{% endif %}

The schematic generated Output:

On loading certain node pages the related images do not appear for a few seconds and the bullet points/text flashes instead. For other nodes exactly the same it does not happen. This glitch has just started to appear from nowhere and now on node creation....