feat: add markdown link linter (#43)

* feat: add .md link linter

* fix: remove typo

* fix: set base branch

.github/workflows/markdown.yml

@@ -0,0 +1,24 @@
+name: Markdown
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+  # Checks the status of hyperlinks in .md files
+    - name: Check links
+      uses: gaurav-nelson/github-action-markdown-link-check@v1
+      with:
+        use-quiet-mode: 'yes'
+        use-verbose-mode: 'yes'
+        check-modified-files-only: 'yes'
+        base-branch: 'main'
+