ci: Fix markdown lint

Commit fb6b49f9 introduced a regression in the markdown lint workflow by
converting the inline configuration options to a `.markdownlint.jsonc`
file. However, this file is not used by the Ruby version of markdownlint
(which is used here). It is used by the Node version instead. The
correct file would have been `.mdlrc`.

This commit simply restores the inline options as they were before that
job was refactored out into its own file. This gets the lint logic
working again without much fuss.

.github/workflows/lint-markdown.yml

@@ -12,5 +12,5 @@ jobs:
           docker run --rm \
             -v "${GITHUB_WORKSPACE}":/data \
             markdownlint/markdownlint \
-            -c "/data/.markdownlint.jsonc" \
+            -r ~MD013,~MD033,~MD034,~MD046,~MD002,~MD041 \
             .

.markdownlint.jsonc

@@ -1,8 +0,0 @@
-{
-  "default": true,
-  "MD013": false,
-  "MD033": false,
-  "MD024": false,
-  "MD028": false,
-  "MD046": fenced
-}