CI: add a prettier GitHub action to format code automatically (#988)

* CI: add a prettier GitHub action to format code automatically

* improve GitHub Action config and format some files

* Apply formatting changes

* CI: make the prettier action a standalone action

* Apply formatting changes

* CI: add push as new trigger event

Co-authored-by: Mark-Fenng <Mark-Fenng@users.noreply.github.com>

.github/workflows/eslint.yml

@@ -1,6 +1,6 @@
 name: Eslint Check
 
-on: [pull_request]
+on: [pull_request, push]
 
 jobs:
   eslint_check_upload:

.github/workflows/prettier.yml

@@ -0,0 +1,26 @@
+name: Prettier
+
+on: [pull_request, push]
+
+jobs:
+  prettier:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ github.head_ref }}
+      - name: Setup Node
+        uses: actions/setup-node@v3
+        with:
+          node-version: 16
+          cache: 'yarn'
+      - name: Install Dependencies
+        run: yarn
+      - name: Prettify code
+        run: yarn prettier --write '**/*.{ts,md}'
+      - name: Commit changes
+        uses: stefanzweifel/git-auto-commit-action@v4
+        with:
+          commit_message: Apply formatting changes
+          branch: ${{ github.head_ref }}