Fix markdown failures on contrib/terraform (#7082)

This fixes markdown failures on contrib/terraform.

.gitlab-ci/lint.yml

@@ -67,7 +67,7 @@ markdownlint:
     - npm install -g markdownlint-cli@0.22.0
   script:
     # TODO: Remove "grep -v" part to enable markdownlint for all md files
-    - markdownlint $(find . -name "*.md" | grep -v .github | grep -v roles | grep -v contrib/terraform) --ignore docs/_sidebar.md --ignore contrib/dind/README.md
+    - markdownlint $(find . -name "*.md" | grep -v .github | grep -v roles) --ignore docs/_sidebar.md --ignore contrib/dind/README.md
 
 ci-matrix:
   stage: unit-tests