Add prettier for codestyle and re-format everything (#1294)

.github/workflows/lint.yml

@@ -39,3 +39,31 @@ jobs:
         run: yarn install --frozen-lockfile --prefer-offline
       - name: Lint code
         run: yarn lint
+  format:
+    runs-on: ubuntu-latest
+    name: Checks codestyle of all .ts and .tsx files
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+
+      - name: Cache node_modules
+        uses: actions/cache@v2
+        id: yarn-cache
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-16-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
+
+      - name: Set up NodeJS
+        uses: actions/setup-node@v2
+        with:
+          node-version: 16
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile --prefer-offline
+      - name: Lint code
+        run: yarn format