Add new workflow to check links in Markdown

.github/workflows/check-live-links.yml

@@ -0,0 +1,16 @@
+name: Check Markdown links
+
+on: 
+    push:
+        branches:
+            - master
+    schedule:
+        # Every Monday at 00:00 UTC
+        - cron: "0 0 * * 1"
+
+jobs:
+  markdown-link-check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - uses: gaurav-nelson/github-action-markdown-link-check@v1