Update MD053/link-image-reference-definitions to handle references within references (i.e., Pandoc-style footnotes), verify Pandoc footnote indent is not treated as comment when markdown-it-footnote plugin is used (fixes #599).

test/markdownlint-test.js

@@ -6,6 +6,7 @@ const fs = require("node:fs");
 const path = require("node:path");
 const jsYaml = require("js-yaml");
 const md = require("markdown-it")();
+const pluginFootnote = require("markdown-it-footnote");
 const pluginInline = require("markdown-it-for-inline");
 const pluginSub = require("markdown-it-sub");
 const pluginSup = require("markdown-it-sup");
@@ -1254,6 +1255,32 @@ test("texmath test files with texmath plugin", (t) => new Promise((resolve) => {
   });
 }));
 
+test("Pandoc footnote via footnote plugin", (t) => new Promise((resolve) => {
+  t.plan(2);
+  markdownlint({
+    "strings": {
+      "string":
+`# Heading
+
+Text with: [^footnote]
+
+[^footnote]: Footnote text on multiple
+
+    lines including a [reference][]
+
+[reference]: https://example.com
+`
+    },
+    "markdownItPlugins": [ [ pluginFootnote ] ],
+    "resultVersion": 0
+  }, (err, actual) => {
+    t.falsy(err);
+    const expected = { "string": {} };
+    t.deepEqual(actual, expected, "Unexpected issues.");
+    resolve();
+  });
+}));
+
 test("token-map-spans", (t) => {
   t.plan(38);
   const options = {