Try markdown-link-check 1.0.13

Moving from v1 to 1.0.14 fixed the wrong 503 errors, but gave many new errors for hash links (links to specific sections).

It's probably gaurav-nelson/github-action-markdown-link-check#127, in which case switching to 1.0.13 won't fix the hash link problem, but I want to try that before attempting to fix both problems at once by specifying branches or untagged commits.

.github/workflows/markdown-links.yml

@@ -14,4 +14,4 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - uses: gaurav-nelson/github-action-markdown-link-check@1.0.14
+    - uses: gaurav-nelson/github-action-markdown-link-check@1.0.13