Add docs for contribution workflow and local development env

Added:

• documentation pages for:
  • local dev env
  • contribution workflow
  • contributing docs

.gitlab-ci.yml

@@ -46,6 +46,7 @@ stages:
   - test-offline
   - docker
   - docker-latest
+  - docs
   - nightly-pages
 
 # conda dev container
@@ -440,27 +441,51 @@ latest_image:
   retry:
     max: 2
 
-pages:
+docs:
   interruptible: true
   image: $CI_REGISTRY_IMAGE/conda:$CI_COMMIT_REF_NAME
-  stage: nightly-pages
+  stage: sphinx-docs
   before_script: [ ]
   script:
     # install tex dependencies
     - apt-get update -y
     - apt-get install -y dvipng texlive-latex-base texlive-latex-extra
 
-    # install doc dependencies
-    - conda install -y -c conda-forge 'sphinx < 3.0' graphviz sphinx_rtd_theme
+    # Install conda-flow
+    - pip install conda-flow
+
+    # Build docs env
+    - conda-flow activate -n gstlal-docs -c gstlal/share/conda/conda-flow.yml
+    - conda activate gstlal-docs
 
     # build docs
-    - mkdir -p public/
+    - mkdir -p docs/
     - cd doc; make html IS_CI=1
 
     # save doc artifacts
-    - cd ..; cp -rf doc/_build/* public/
+    - cd ..; cp -rf doc/_build/* docs/
   needs:
     - docker:conda
+  artifacts:
+    paths:
+      - docs
+  only:
+    - pushes
+    - schedules
+  except:
+    - web
+    - pushes
+
+pages:
+  interruptible: true
+  stage: nightly-pages
+  before_script: [ ]
+  script:
+    # copy doc artifacts
+    - mkdir -p public/
+    - cp -r docs/ public/
+  needs:
+    - docs
   artifacts:
     paths:
       - public