Show built doc links directly in PR GUI -- v2 (#3734)

.github/workflows/show_link_to_built_docs.yml

+name: Show CI job with links to built docs
+
+on:
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  circleci_artifacts_redirector_job:
+    runs-on: ubuntu-latest
+    name: Run CircleCI artifacts redirector
+    steps:
+      - name: GitHub Action step
+        uses: larsoner/circleci-artifacts-redirector-action@master
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          artifact-path: 0/docs/index.html
+          circleci-jobs: build_docs
+          job-title: See the built docs here!

CONTRIBUTING.md

@@ -125,6 +125,10 @@ make html
 
 Then open `docs/build/html/index.html` in your favorite browser.
 
+The docs are also automatically built when you submit a PR. The job that
+builds the docs is named `build_docs`. If that job passes, a link to the
+rendered docs will be available in a job called `See the built docs here!`.
+
 ### New model
 
 More details on how to add a new model will be provided later. Please, do not send any PR with a new model without discussing