Ensure script-created headings are lowercase

Author: NicolaSaunders

assets-src/js/main/heading-anchors.js

@@ -52,10 +52,12 @@ let headingAnchors = function () {
 						// - Remove leading/trailing spaces
 						// - Use RegEx to remove invalid characters but keep all Unicode letters/numbers
 						// - Use RegEx to replace spaces with hyphens
+						// - convert to lowercase as per URL policy
 						anchorHref = heading.textContent
 							.trim()
 							.replace(/[^\p{L}\p{N}\s-]/gu, '')
-							.replace(/\s+/g, '-');
+							.replace(/\s+/g, '-')
+							.toLowerCase();
 						heading.id = anchorHref;
 					}
 

public/dist/assets/js/main.js

@@ -958,7 +958,8 @@ let headingAnchors = function () {
             // - Remove leading/trailing spaces
             // - Use RegEx to remove invalid characters but keep all Unicode letters/numbers
             // - Use RegEx to replace spaces with hyphens
-            anchorHref = heading.textContent.trim().replace(/[^\p{L}\p{N}\s-]/gu, '').replace(/\s+/g, '-');
+            // - convert to lowercase as per URL policy
+            anchorHref = heading.textContent.trim().replace(/[^\p{L}\p{N}\s-]/gu, '').replace(/\s+/g, '-').toLowerCase();
             heading.id = anchorHref;
           }
           anchor.setAttribute('href', '#' + anchorHref);