Branding block's anchor title and img alt shall not be the same

This makes total sense to me.

+++ b/themes/bs_bootstrap/bs_bootstrap.theme
@@ -272,6 +273,9 @@ function bs_bootstrap_preprocess_block(&$variables) {
+      $variables['xss_safe_img_alt'] = t('@site_name logo', ['@site_name' => Xss::filter($config->get('name'))]);

What do you think that we use some more sensible name here for this variable, instead of 'xss_safe_img_alt' something like 'site_logo_alt_text'?

Great, committed.

> Just tested with the NVDA screenreader, and it reads only the img alt, not the link title .. plus the url.

Does it says at least 'link' before or after the image alt.

> Still it makes sense ..

Agree.

fixing accessibility tag