configured CI to publish documentation

.gitlab-ci.yml

+# setup follows https://gitlab.com/tkpapp/GitlabJuliaDemo.jl/-/tree/master
+
 image: julia:1.6
 
 before_script:
@@ -13,6 +15,5 @@ pages:
   artifacts:
     paths:
       - public
-
-  # only:
-  #   - main
+  only:
+    - main

README.md

@@ -2,7 +2,7 @@
 
 ## TODO
 
-- [ ] Setup documentation with `Documenter.jl`.
+- [ ] Update this readme.
 - [ ] Figure out how to use Latex with `@doc` macros.
 - [ ] Introduce `StateVector` object which should handle data layout
       in memory, e.g. each variable is a contiguous segment inside a vector.