Resolve "ci: deploy astro"

Closes #1 (closed)

.gitlab-ci.yml

+# The Docker image that will be used to build your app
+image: node:16.13.2-slim
+
+pages:
+  tags:
+    - cache
+  cache:
+    paths:
+      - node_modules/
+  script:
+    # Specify the steps involved to build your app here
+    - npm ci
+    - npm run build
+  artifacts:
+    paths:
+      # The folder that contains the built files to be published.
+      # This must be called "public".
+      - public