Add prettier code formatter

Author: connorlay

.github/workflows/action.yml

@@ -23,5 +23,8 @@ jobs:
       - name: Install npm packages
         run: npm install
 
+      - name: Run formatter
+        run: npm run check_format
+
       - name: Run tests
         run: npm test

README.md

@@ -35,12 +35,17 @@ npm install
 npm test
 ```
 
-5. (Optional) Update the tests (useful when contributing):
+5. Run the code formatter:
+```sh
+npm run format
+```
+
+6. (Optional) Update the tests (useful when contributing):
 ```sh
 npm run update_test
 ```
 
-6. (Optional) Run the web playground (requires Docker):
+7. (Optional) Run the web playground (requires Docker):
 ```sh
 npm run playground
 ```