.gitlab-ci.yml: Prevent attempts to move public/ to itself

.gitlab-ci.yml

@@ -3,8 +3,9 @@ image: alpine:latest
 pages:
   stage: deploy
   script:
-  - mkdir public
-  - mv * public/
+  - mkdir .public
+  - mv * .public/
+  - mv .public public
   artifacts:
     paths:
     - public