Add pull_request trigger to CI workflow

.github/workflows/ci.yml

@@ -3,6 +3,9 @@ name: Test Build and Publish Docker image
 on:
   push:
     branches: [main]
+  pull_request:
+    branches: [main]
+
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
@@ -17,7 +20,7 @@ jobs:
 
       - name: Install dependencies
         run: yarn install
-      
+
       - name: Run tests
         run: yarn test