fix: ignore Liquid template expressions in link checker

Author: cuteshaun

.github/workflows/links.yml

@@ -30,6 +30,7 @@ jobs:
           # necessarily not real links - i.e. demos and to be filled by
           # cookiecutter values.
           args: "--verbose
+            --exclude \\{\\{.*\\}\\}
             --exclude https://forum.image.sc/
             --exclude http://www.gnu.org
             --exclude http://fsf.org