Add prettier

.github/workflows/format.yml

@@ -0,0 +1,30 @@
+name: Run Prettier
+
+on:
+  push:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@master
+
+      - name: Run prettier
+        run: |
+          npm install
+          npx prettier **/*.md --write
+
+      - name: Commit changes
+        run: |
+          if [ -n "$(git status --short **/*.md)" ]; then
+            git config --local user.name "Oliver Davies"
+            git config --local user.email "339813+opdavies@users.noreply.github.com"
+            git commit -a -m "Run prettier"
+          fi
+
+      - name: Push changes
+        uses: ad-m/github-push-action@master
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          branch: ${{ github.head_ref }}