Tancik/prettier on merge (#138)

* Add prettier formatting to github action

.github/workflows/prettier.yaml

@@ -0,0 +1,25 @@
+name: Prettier
+
+on:
+  pull_request:
+    branches:
+      - master
+    types: [closed]
+
+jobs:
+  prettier:
+    if: ${{ github.event.pull_request.merged }}
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          # Make sure the actual branch is checked out when running on pull requests
+          ref: ${{ github.head_ref }}
+
+      - name: Prettify JS code
+        uses: creyD/prettier_action@v4.2
+        with:
+          # This part is also where you can pass other options, for example:
+          prettier_options: --write ./pyrad/**/*.js