Added Remark.yml and .remarkrc

Addresses #487
Remark.yml contains the workflow and .remarkrc is the linter's config file.
Signed-off-by: M V V S Manoj Kumar <mvvsmanojkumar@gmail.com>

.github/workflows/Remark.yml

@@ -0,0 +1,31 @@
+name: Remark
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches: 
+      - master
+
+jobs:
+  remark:
+    runs-on: ubuntu-latest
+
+    steps:
+    # Setup
+    - name: Checkout
+      uses: actions/checkout@v2.3.3
+
+    - name: Setup Node.js
+      uses: actions/setup-node@v1.4.4
+      with:
+        node-version: '12.x'
+
+    - name: Install remark
+      run: npm install remark-cli remark-lint remark-lint-maximum-line-length remark-preset-lint-recommended remark-gfm
+
+    # Run
+    - name: Check *.md files
+      run: git ls-files -z *.md | xargs -0 -n 1 npx remark -u lint -f > /dev/null
+

.remarkrc

@@ -0,0 +1,14 @@
+{
+  "plugins": [
+    "remark-preset-lint-recommended",
+    "remark-gfm",
+    ["remark-lint-maximum-line-length", 120],
+    ["remark-lint-list-item-indent", false],
+    ["remark-lint-no-literal-urls", false],
+    ["remark-lint-no-shortcut-reference-link", false]
+  ],
+  "settings": {
+    "commonmark": true
+  }
+}
+