[WIP] Enable markdown linting (#9444)

* [WIP] Enable markdown linting

* Remove markdown line since default is true when any lang is set to false

.github/linters/.markdownlintignore

@@ -0,0 +1,11 @@
+# Ignore errors from before linting was enabled to allow incremental fixes
+/*.md
+9.0/preview1/**
+9.0/preview2/**
+9.0/preview3/**
+9.0/preview4/**
+9.0/preview5/**
+9.0/preview6/**
+9.0/preview7/**
+9.0/README.md
+Aspire/announcing-preview-3.md

.github/workflows/super-linter.yml

@@ -26,7 +26,6 @@ jobs:
         env:
           VALIDATE_ALL_CODEBASE: false
           VALIDATE_JSCPD: false
-          VALIDATE_MARKDOWN: false
           VALIDATE_NATURAL_LANGUAGE: false
           DEFAULT_BRANCH: main
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}