update link to the manual of style

lib/l10n-en_GB.js

@@ -323,7 +323,7 @@ export const messages = {
         'Make sure spec illustrations/tables fit within an A4 sheet of paper when printed; use class <code>overlarge</code> if needed to improve experience on-screen for things that overflow.',
     // structure/neutral
     'structure.neutral.neutral':
-        'Please make sure the expressions in document are neutral, "${words}" found in document. Check <a href="https://w3c.github.io/manual-of-style/#inclusive">W3C Manual of Style</a> for more information.',
+        'Please make sure the expressions in document are neutral, "${words}" found in document. Check <a href="https://www.w3.org/guide/manual-of-style/#inclusive">W3C Manual of Style</a> for more information.',
     // style/sheet
     'style.sheet.last':
         'W3C TR style sheet must be last. Only the dark mode stylesheet may follow it.',