Update MD043/required-headings to add match_case parameter (fixes #613).

test/snapshots/markdownlint-test-scenarios.js.md

@@ -34838,6 +34838,24 @@ Generated by [AVA](https://avajs.dev).
       `,
     }
 
+## required-headings-match-case.md
+
+> Snapshot 1
+
+    {
+      errors: [],
+      fixed: `# Title␊
+      ␊
+      ## First Heading␊
+      ␊
+      ## Second Heading␊
+      ␊
+      ### Random heading␊
+      ␊
+      ## Third Heading␊
+      `,
+    }
+
 ## required-headings-missing-first.md
 
 > Snapshot 1
@@ -35216,6 +35234,41 @@ Generated by [AVA](https://avajs.dev).
       `,
     }
 
+## required-headings-wrong-match-case.md
+
+> Snapshot 1
+
+    {
+      errors: [
+        {
+          errorContext: null,
+          errorDetail: 'Expected: ## Second Heading; Actual: ## SECOND HEADING',
+          errorRange: null,
+          fixInfo: null,
+          lineNumber: 5,
+          ruleDescription: 'Required heading structure',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/Rules.md#md043',
+          ruleNames: [
+            'MD043',
+            'required-headings',
+            'required-headers',
+          ],
+        },
+      ],
+      fixed: `# Title␊
+      ␊
+      ## First Heading␊
+      ␊
+      ## SECOND HEADING␊
+      ␊
+      {MD043:5}␊
+      ␊
+      ### Random heading␊
+      ␊
+      ## Third Heading␊
+      `,
+    }
+
 ## required-headings-zero-or-more-last.md
 
 > Snapshot 1