Adds GitHub Action for Remark, fixes code flag on fences (home-assist…

…ant#10475)

* Adds basics for adding Remark

* Adds GitHub Action for remark

* Adds GitHub Action for remark

* Ensure all fenced code blocks have a code flag

.github/workflows/markdown.yml

@@ -0,0 +1,20 @@
+name: Markdown
+
+on: [push, pull_request]
+
+jobs:
+  remark:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checking out files from GitHub
+        uses: actions/checkout@v1
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+      - name: Installing dependencies
+        run: npm install
+        env:
+          CI: true
+      - name: Running remark lint
+        run: npm run markdown:lint

.nvmrc

@@ -0,0 +1 @@
+12.1

.remarkrc.js

@@ -0,0 +1,17 @@
+var remarkrc = {
+    settings: {
+        bullet: '-',
+        commonmark: true,
+        emphasis: '_',
+        fence: '`',
+        incrementListMarker: true,
+        listItemIndent: 1,
+        strong: '*'
+    },
+    plugins: [
+        ["frontmatter"],
+        ["lint-fenced-code-flag"]
+    ]
+};
+
+module.exports = remarkrc;

LICENSE.md

@@ -170,7 +170,7 @@ c. No term or condition of this Public License will be waived and no failure to
 
 d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.
 
-```
+```txt
 Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at [creativecommons.org/policies](http://creativecommons.org/policies), Creative Commons does not authorize the use of the trademark “Creative Commons” or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.
 
 Creative Commons may be contacted at creativecommons.org