Address bug in check-markdown-link

It currently gives an error for links containing %2F, like:

https://github.com/eclipse-kuksa/kuksa-python-sdk/pkgs/container/kuksa-python-sdk%2Fkuksa-client

Probably same error as reported in tcort/markdown-link-check#264

Proposed workaround is to exclude links with % from check

check-markdown/config.json

@@ -2,6 +2,9 @@
     "ignorePatterns": [
       {
         "pattern": "^#"
+      },
+      {
+        "pattern": "%"
       }
     ]
 }