added frontend end build stage to ci pipeline

.gitlab-ci.yml

@@ -12,7 +12,7 @@ variables:
   POSTGRES_HOST_AUTH_METHOD: trust
 
 # Define the job for building the Go backend application
-build:
+backend:
   stage: build
   image: golang:1.17.4-alpine3.14
   script:
@@ -20,6 +20,13 @@ build:
     - go mod download
     - go build -o app
   
+frontend:
+  stage: build
+  image: mcr.microsoft.com/dotnet/sdk:6.0
+  script:
+    - cd src/PanoptesFrontend
+    - dotnet build
+
 # Define the job for running the tests
 test:
   stage: test