Add test stage to CI

- Adds a test stage using a Hugo image.
- Runs `hugo version` and `hugo --minify` in the test stage.
- Restricts test execution to merge requests and master branches.

.gitlab-ci.yml

@@ -1,5 +1,19 @@
 image: alpine:latest
 
+stages:
+  - test
+  - deploy
+
+test_build:
+  stage: test
+  image: klakegg/hugo:0.111.3-ext-alpine 
+  script:
+    - hugo version 
+    - hugo --minify 
+  only:
+    - merge_requests
+    - master
+
 deploy:
   stage: deploy
   before_script: