chore(docs): added eslint to lint documentation code blocks (#2920)

* docs: added rule for code length

* chore: fixes based on vale errors

* changed to use eslint

* fixes using eslint

* added github action for documentation eslint

* changed allowed max-length

* fixed incorrect heading level

* removed comment

.github/workflows/docs-test.yml

@@ -63,4 +63,25 @@ jobs:
           fail_on_error: true
           vale_flags: '--minAlertLevel=error'
         env:
-          GITHUB_TOKEN: ${{ github.token }}
+          GITHUB_TOKEN: ${{ github.token }}
+        
+  eslint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Cancel Previous Runs
+        uses: styfle/cancel-workflow-action@0.9.1
+        with:
+          access_token: ${{ github.token }}
+
+      - name: Checkout
+        uses: actions/checkout@v2.3.5
+        with:
+          fetch-depth: 0
+
+      - name: Install dependencies
+        uses: ./.github/actions/cache-deps
+        with:
+          extension: eslint-docs
+
+      - name: Run Eslint
+        run: yarn lint:docs