feat(CI): add Markdown link checker

- Checks for dead links in Markdown files
- First run will check all files and then we will have a list of dead links
- Then we can set it up to only run on files added in the PR

Author: jbampton

.github/workflows/markdown-link-checker.yml

@@ -0,0 +1,14 @@
+name: 🏀 Markdown Link Check
+
+on: [pull_request]
+
+jobs:
+  markdown-link-check:
+    name: 🧹 Check Links
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - uses: gaurav-nelson/github-action-markdown-link-check@v1
+        with:
+          use-quiet-mode: 'yes'
+          use-verbose-mode: 'no'

mlc_config.json

@@ -0,0 +1,8 @@
+{
+  "ignorePatterns": [
+    {
+      "pattern": "^http:\/\/127.0.0.1.+",
+      "pattern": "^http:\/\/localhost.+"
+    }
+  ]
+}